Selective passivation and selective deposition

ABSTRACT

Methods for selective deposition are provided. Material is selectively deposited on a first surface of a substrate relative to a second surface of a different material composition. An inhibitor, such as a polyimide layer, is selectively formed from vapor phase reactants on the first surface relative to the second surface. A layer of interest is selectively deposited from vapor phase reactants on the second surface relative to the first surface. The first surface can be metallic while the second surface is dielectric. Accordingly, material, such as a dielectric transition metal oxides and nitrides, can be selectively deposited on metallic surfaces relative dielectric surfaces using techniques described herein.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

The present application is a continuation of U.S. application Ser. No.17/470,177, filed Sep. 9, 2021, which is a continuation of U.S.application Ser. No. 16/588,600, filed Sep. 30, 2019, now U.S. Pat. No.11,145,506, issued Oct. 12, 2021, which claims priority to U.S.Provisional Application No. 62/805,471, filed Feb. 14, 2019, and U.S.Provisional Application No. 62/740,124, filed Oct. 2, 2018, each ofwhich is incorporated by reference herein.

BACKGROUND Field

The present disclosure relates generally to selective deposition ofmaterials on a first surface of a substrate relative to a second surfaceof a different material composition.

Description of the Related Art

The shrinking device dimensions in semiconductor manufacturing call fornew innovative processing approaches. Conventionally, patterning insemiconductor processing involves subtractive processes, in whichblanket layers are deposited, masked by photolithographic techniques,and etched through openings in the mask. Additive patterning is alsoknown, in which masking steps precede deposition of the materials ofinterest, such as patterning using lift-off techniques or damasceneprocessing. In most cases, expensive multi-step lithographic techniquesare applied for patterning.

Patterning could be simplified by selective deposition, which has gainedincreasing interest among semiconductor manufacturers. Selectivedeposition would be highly beneficial in various ways. Significantly, itcould allow a decrease in lithography steps, reducing the cost ofprocessing. Selective deposition could also enable enhanced scaling innarrow structures, such as by making bottom up fill possible.Electrochemical deposition is one form of selective deposition, asmetals can be formed selectively on conductive elements. Chemical vapordeposition (CVD) and atomic layer deposition (ALD) are surface-sensitivetechniques vapor deposition techniques and therefore have beeninvestigated as good candidates for selective deposition. Selective ALDwas suggested, for example, in U.S. Pat. No. 6,391,785.

One of the challenges with selective deposition is selectivity fordeposition processes are often not high enough to accomplish the goalsof selectivity. Surface pretreatment is sometimes available to eitherinhibit or encourage deposition on one or both of the surfaces, butoften such treatments themselves call for lithography to have thetreatments applied or remain only on the surface to be treated.

Accordingly, a need exists for more practical processes foraccomplishing selective deposition.

SUMMARY OF INVENTION

In one aspect a method is provided for selective deposition on a secondsurface of a substrate relative to a first surface of the substrate,where the first and second surfaces have different compositions. Themethod includes, in order: selectively forming an inhibitor layer fromvapor phase reactants on the first surface relative to the secondsurface; baking the inhibitor layer; and selectively depositing a layerof interest from vapor phase reactants on the second surface relative tothe passivation layer.

In some embodiments, the method additionally includes treating the firstand second surfaces prior to selectively forming the inhibitor layer. Insome embodiments, the method includes wherein treating includes exposingthe substrate to a plasma. In some embodiments, treating includesexposing the substrate to a silane, such as an alkylaminosilane. In someembodiments, treating includes exposing the substrate toN-(trimethylsilyl)dimethylamine (TMSDMA) or trimethylchlorosilane. Insome embodiment, the method further includes cleaning the second surfaceto remove any inhibitor after selectively forming the inhibitor layer.In some embodiments, the method includes wherein cleaning comprisestreatment with hydrogen plasma. In some embodiments, baking includesheating the substrate to a temperature of from about 300 to 400° C.

In some embodiments, the method further includes cleaning the first andsecond surfaces after selectively depositing the layer of interest. Insome embodiments, cleaning includes treating the surfaces with hydrogenplasma. In some embodiments, the method further includes whereinselectively forming an inhibitor layer includes selectively vapordepositing an organic layer on the first surface. In some embodiments,the organic layer is a polyimide layer.

In some embodiments, the layer of interest is selectively deposited byan atomic layer deposition process. In some embodiments, the firstsurface comprises a metal or metallic material and the second surfacecomprises a dielectric material.

In some embodiments, wherein the layer of interest comprises a metaloxide. In some embodiments, the metal oxide comprises zirconium oxide,hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, yttriumoxide, lanthanum oxide, or other transition metal oxide or mixturesthereof. In some embodiments, the metal oxide comprises a dielectrictransition metal oxide. In some embodiments, the metal oxide comprisesaluminum oxide. In some embodiments, the aluminum oxide is depositedusing an aluminum precursor comprising trimethyl aluminum (TMA),dimethylaluminumchloride, aluminum trichloride (AlCl₃), dimethylaluminumisopropoxide (DMAI) or triethyl aluminum (TEA). In some embodiments, thealuminum oxide is deposited using an aluminum precursor comprising aheteroleptic aluminum compound comprising an alkyl group and anotherligand, such as a halide, for example Cl. In some embodiments, thealuminum oxide is deposited using an aluminum precursor comprising analuminum alkyl compound comprising two different alkyl groups asligands. In some embodiments, the aluminum compound is deposited usingan aluminum precursor comprising a metalorganic aluminum compound or anorganometallic aluminum compound.

In some embodiments, the layer of interest comprises a metal nitride. Insome embodiments, the metal nitride is titanium nitride. In someembodiments, the titanium nitride is deposited by a vapor depositionprocess from TiCl₄ and NH₃.

In another aspect, a cluster tool is provided for selective depositionof a layer of interest on a second surface of a substrate relative to afirst surface of the substrate, where the first and second surfaces havedifferent compositions. The cluster tool includes: a first moduleconfigured for pretreating the substrate; a second module configured fortreating the substrate with plasma; a third module configured for vapordeposition of an inhibitor on the first surface of the substraterelative to the second surface of the substrate; and a fourth moduleconfigured for vapor deposition of the layer of interest.

In another aspect, a system is provided for selective deposition of adielectric on a second surface of a substrate relative to a firstsurface of the substrate. The system includes: a first chamberconfigured for selective deposition of an organic passivation layer andfor partial etch-back of the organic passivation layer; and a secondchamber configured for selective deposition of the dielectric on thesecond surface relative to the first surface of the substrate.

In another aspect, a system is provided for selective deposition of afilm of interest on a second surface of a substrate relative to thefirst surface of the substrate. The system includes: a first chamberconfigured for pretreating the substrate and for etch processing; asecond chamber configured for selective deposition of an organicpassivation layer; and a third chamber configured for selectivedeposition of the film of interest on a second surface of the substraterelative to the first surface of the substrate.

In some embodiments, the third chamber is further configured for a bakeprocess. In some embodiments, the system further includes a fourthchamber configured for a bake process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic cross section of a portion of a substrate havingfirst and second surfaces of different compositions, in accordance witha first embodiment.

FIG. 1B is a schematic cross section of the substrate of FIG. 1A after aselective passivation of the first surface.

FIG. 1C is a schematic cross section of the substrate of FIG. 1B afterselective deposition on the second surface.

FIG. 1D is a schematic cross section of the substrate of FIG. 1C afterremoval of the passivation material from the first surface.

FIG. 2A is a schematic cross section of a portion of a substrate havingfirst and second surfaces of different compositions, with a passivationblocking material formed on the second surface, in accordance with asecond embodiment.

FIG. 2B is a schematic cross section of the substrate of FIG. 2A after aselective passivation of the first surface.

FIG. 2C is a schematic cross section of the substrate of FIG. 2B afterremoval of the passivation blocking material from the second surface.

FIG. 2D is a schematic cross section of the substrate of FIG. 2C afterselective deposition on the second surface.

FIG. 2E is a schematic cross section of the substrate of FIG. 2D afterremoval of the passivation material from the first surface.

FIG. 3A is a schematic cross section of the substrate of FIG. 2D afterselective deposition of a further material over the second surface, inaccordance with a third embodiment.

FIG. 3B is a schematic cross section of the substrate of FIG. 3A afterremoval of the passivation material from the first surface.

FIG. 4A is a flow diagram generally illustrating processes forselectively depositing an organic passivation layer.

FIG. 4B is a flow diagram generally illustrating atomic layer deposition(ALD) processes for selectively depositing an organic layer.

FIG. 5 is a schematic illustration of an apparatus configured forselective deposition of a polymer layer and in situ etch back fromundesired surfaces.

FIG. 6 is a flow diagram generally illustrating processes forselectively depositing a dielectric layer on second surfaces afterselective passivation of first surfaces with organic material inaccordance with embodiments.

FIG. 7 is a flow diagram utilizing schematic cross sections of a portionof a substrate having first and second surfaces of differentcompositions, and generally illustrates the effect that the extent ofetch back on the passivation material has on the relationship of thedielectric layer formed with the interface of the first and secondsurfaces.

FIG. 8 is a flow diagram utilizing schematic cross sections of a portionof a substrate having first and second surfaces of differentcompositions, and generally illustrates the effect passivation layerthickness has on the relationship of the dielectric layer formed withthe interface of the first and second surfaces.

FIG. 9 is a flow diagram utilizing schematic cross sections of a portionof a substrate having first and second surfaces of differentcompositions, and generally illustrates the effect dielectric thicknesshas on the relationship of the dielectric layer formed with theinterface of the first and second surfaces.

FIG. 10A is a schematic cross section of a portion of substrate havingflush first and second surfaces of different compositions withpassivation and dielectric layers selectively deposited thereover,respectively.

FIG. 10B is a schematic cross section of a portion of substrate havingfirst and second surfaces of different compositions with the firstsurfaces recessed relative to the second surfaces and passivation anddielectric layers selectively deposited thereover, respectively.

FIG. 10C is a schematic cross section of a portion of substrate havingfirst and second surfaces of different compositions with first surfaceselevated relative to the second surfaces and with passivation anddielectric layers selectively deposited thereover, respectively.

FIG. 10D is a schematic cross section of a portion of substrate havingfirst and second surfaces of different compositions with first surfacesrecessed relative to the second surfaces and with passivation anddielectric layers selectively deposited thereover, respectively.

FIG. 11A is a schematic cross section of a portion of a substrate withan embedded metal feature.

FIG. 11B is a schematic cross section of the substrate of FIG. 11A afterformation of a metal cap to define a first surface.

FIG. 11C is a schematic cross section of the substrate of FIG. 11B afterselective passivation deposition and etch back, leaving a passivationfilm over the metal cap with edges of the metal cap exposed.

FIG. 11D is a schematic cross section of the substrate of FIG. 11C afterselective deposition of a dielectric material over low k surfaces of thesubstrate, where the deposited dielectric resists etching of low kmaterials and overlaps with the metal cap.

FIG. 11E is a schematic cross section of the substrate of FIG. 11D afterremoval of the passivation layer.

FIG. 12A is a flow diagram showing schematic cross sections of a portionof a substrate having first and second surfaces of differentcompositions, and generally illustrates selective passivation of thefirst surfaces, etch back in a manner that leaves the passivationoverlapping with the second surfaces, and selective deposition of adielectric etch mask on the remainder of the second surfaces.

FIG. 12B are schematic cross sections of the substrate of FIG. 12A,following removal of the passivation layers, leaving gaps between thefirst surfaces and the dielectric etch mask, selective etching of thelow k material exposed in the gaps, and deposition to leave air-gapswithin the substrate.

FIG. 13 is a flow diagram illustrating a process flow for selectivedeposition.

FIG. 14 is a flow diagram illustrating a process flow for selectivedeposition on a three-dimensional structure such as a trench or via.

DETAILED DESCRIPTION OF EMBODIMENTS

Methods and apparatus are disclosed for selectively depositing materialover a second surface relative to a first surface, where the first andsecond surfaces have material differences. For example, one of thesurfaces can include a metallic material and the other surface caninclude an inorganic dielectric material. In embodiments describedherein, an organic passivation layer is deposited selectively on thefirst surface relative to the second surface. In some embodiments, thefirst surface is metallic and the second surface is dielectric; in otherembodiments the first surface is dielectric and second surface ismetallic. Subsequently, a layer of interest is selectively deposited onthe second surface relative to the organic passivation layer. In someembodiments the layer of interest may be an Al₂O₃ layer. In someembodiments the layer of interest may be a TiN layer. Further layers canbe selectively deposited on the layer of interest, over the secondsurface, relative to the organic passivation layer.

In one embodiment, the first surface comprises a metallic surface, suchas an elemental metal or metal alloy, while the second surface comprisesan inorganic dielectric surface, such as low-k material. Examples oflow-k material include silicon oxide based materials, including grown ordeposited silicon dioxide, doped and/or porous oxides, native oxide onsilicon, etc. A polymer passivation layer is selectively deposited onthe metallic surface relative to the inorganic dielectric surface.Subsequently, a layer of interest is selectively deposited on theinorganic dielectric surface. The layer of interest may include a metalelement. Examples of the layer of interest include dielectrics, such aszirconium oxide (e.g., ZrO₂), hafnium oxide (e.g., HfO₂), aluminum oxide(e.g. Al₂O₃), titanium nitride (e.g., TiN) and titanium oxide (e.g.,TiO₂). Processes are provided for selectively depositing such materialson silicon-oxide based surfaces relative to polymer surfaces.

In a second embodiment, the first surface comprises an inorganicdielectric surface, such as low-k material, while the second surfacecomprises a metallic surface, such as an elemental metal or metal alloy.Examples of low-k material include silicon oxide based materials,including grown or deposited silicon dioxide, doped and/or porousoxides, native oxide on silicon, etc. A polymer passivation layer isselectively deposited on the inorganic dielectric surface relative tometallic surface. Prior to depositing the polymer passivation layer, themetallic surface can be provided with a passivation blocking layer, suchas a self-assembled monolayer (SAM). The passivation blocking layerfacilitates selectivity for the polymer deposition on inorganicdielectric surface, and can be removed thereafter to permit selectivedeposition of a layer of interest on the metallic surface relative tothe polymer passivation layer. The layer of interest may include a metalelement. Examples of the layer of interest include metal layers (e.g.,see U.S. Pat. No. 8,956,971, issued Feb. 17, 2015 and U.S. Pat. No.9,112,003, issued Aug. 18, 2015), metal nitride layers (e.g., titaniumnitride) and metal oxide layers (e.g., zirconium oxide, hafnium oxide,titanium oxide and aluminum oxide). Processes are provided forselectively depositing such materials on metallic surfaces relative topolymer surfaces.

In a third embodiment, the process of the second embodiment is conductedto provide a layer of interest selectively over a metallic surfacerelative to a polymer-passivated inorganic dielectric surface.Thereafter, a further layer of interest is selectively deposited overthe layer of interest while the polymer remains passivating theinorganic dielectric surface. For example, the layer of interest maycomprise a metal layer while the further layer of interest comprises ametal oxide layer (e.g., zirconium oxide, hafnium oxide, titaniumoxide). Processes are provided for selectively depositing such materialson metallic surfaces relative to polymer surfaces.

The polymer passivation layer may be removed from the first surfacefollowing selective deposition of the layer(s) of interest over thesecond surface. For example, oxidation processes may selectively removepolymer materials. Conditions are chosen to avoid damage to surroundingmaterials on the substrate.

Embodiments are also provided for controlling the edge profiles and edgepositions for selectively deposited layers relative to other features onthe substrate, such as the boundaries between underlying metallic anddielectric surfaces. Accordingly, control is provided over relativepositioning of selective layer edges without the need for expensivelithographic patterning. Examples illustrate applications for suchcontrol, including examples in which the selective layer overlaps thematerial on which deposition is minimized; examples in which theselective layer is formed with a gap spacing the layer from the materialon which deposition is minimized; and examples in which the edge of theselective layer aligns with the boundary between the two disparateunderlying materials.

Substrate Surfaces

According to some aspects of the present disclosure, selectivedeposition can be used to deposit films of interest on a second surfacerelative to a first surface. The two surfaces can have differentmaterial properties that permit selective formation of an organicmaterial thereon, such as selective deposition of a polymer layer on thefirst surface relative to the second surface, which in turn permitssubsequent selective deposition of a layer of interest on the secondsurface relative to the organic-passivated first layer.

For example, in embodiments described herein, one of the surfaces can bea conductive (e.g., metal or metallic) surface of a substrate, while theother surface can be a non-conductive (e.g., inorganic dielectric)surface of the substrate. In some embodiments, the non-conductivesurface comprises —OH groups, such as a silicon oxide-based surface(e.g., low-k materials, including grown and deposited silicon-oxidematerials and native oxide over silicon). In some embodiments thenon-conductive surface may additionally comprise —H terminations, suchas an HF dipped Si or HF dipped Ge surface. In such embodiments, thesurface of interest will be considered to comprise both the —Hterminations and the material beneath the —H terminations

For any of the examples noted above, the material differences betweenthe two surfaces are such that vapor deposition methods can selectivelydeposit the organic passivation layer on the first surface relative tothe second surface. In some embodiments, cyclical vapor deposition isused, for example, cyclical CVD or atomic layer deposition (ALD)processes are used. In some embodiments, selectivity for the organicpassivation layer can be achieved without passivation/blocking agents onthe surface to receive less of the organic layer; and/or withoutcatalytic agents on the surface to receive more of the organic layer.For example, in embodiments where the first surface is metallic and thesecond surface is dielectric, polymers can be selectively depositeddirectly on metallic surfaces relative to inorganic dielectric surfaces.In other embodiments, where the first surface is dielectric and thesecond surface is metallic, the second surface is first treated toinhibit polymer deposition thereover. For example, a passivationblocking self-assembled monolayer (SAM) can be first formed over ametallic surface relative, facilitating selective deposition of apolymer passivation layer on a dielectric surface, such as an inorganicdielectric surface, relative to a SAM-covered second metallic surface.After selective deposition of the organic passivation is completed,further selective deposition of materials of interest, such as metaloxide or metal layers, can be conducted on the non-passivated secondsurface relative to the passivated first surface.

For embodiments in which one surface comprises a metal whereas the othersurface does not, unless otherwise indicated, if a surface is referredto as a metal surface herein, it may be a metal surface or a metallicsurface. In some embodiments, the metal or metallic surface may comprisemetal, metal oxides, and/or mixtures thereof. In some embodiments, themetal or metallic surface may comprise surface oxidation. In someembodiments, the metal or metallic material of the metal or metallicsurface is electrically conductive with or without surface oxidation. Insome embodiments, metal or a metallic surface comprises one or moretransition metals. In some embodiments, the metal or metallic surfacecomprises one or more of Al, Cu, Co, Ni, W, Nb, Fe, or Mo. In someembodiments, a metallic surface comprises titanium nitride. In someembodiments, the metal or metallic surface comprises one or more noblemetals, such as Ru. In some embodiments, the metal or metallic surfacecomprises a conductive metal oxide, nitride, carbide, boride, orcombination thereof. For example, the metal or metallic surface maycomprise one or more of RuO_(x), NbC_(x), NbB_(x), NiO_(x), CoO_(x),NbO_(x), MoO_(x), WO_(x), WNC_(x), TaN, or TiN.

In some embodiments, a metal or metallic surface comprises cobalt (Co),copper (Cu), tungsten (W) or molybdenum (Mo). In some embodiments, themetal or metallic surface may be any surface that can accept orcoordinate with the first or second precursor utilized in a selectivedeposition process of either the organic passivation layer or the layerof interest, as described herein, depending upon the embodiment.

In some embodiments an organic passivation material, such as apolyimide, is selectively deposited on a metal surface, such as a Co,Cu, W, or Mo surface. In some embodiments, selective deposition of theorganic passivation material on the metal surface occurs at a growthrate of about 0.5 Å/cycle to about 20 Å/cycle, about 1 Å/cycle to about15 Å/cycle, about 1.5 Å/cycle to about 10 Å/cycle, or about 2 Å/cycle toabout 8 Å/cycle. In some embodiments the growth rate of the organicpassivation material on the metal surface is more than about 0.5Å/cycle, more than about 1 Å/cycle, more than about 3 Å/cycle, more thanabout 5 Å/cycle while on the upper end the growth rate in someembodiments is less than about 20 Å/cycle, less than about 15 Å/cycle,less than about 10 Å/cycle or less than about 8 Å/cycle. Selectivity forthe metal surface relative to a second surface is maintained at thesegrowth rates in some embodiments.

In some embodiments, an organic passivation material is selectivelydeposited on a metal oxide surface relative to other surfaces. A metaloxide surface may be, for example a WO, TiO_(x), surface. In someembodiments, a metal oxide surface is an oxidized surface of a metallicmaterial. In some embodiments, a metal oxide surface is created byoxidizing at least the surface of a metallic material using oxygencompound, such as compounds comprising O₃, H₂O, H₂O₂, O₂, oxygen atoms,plasma or radicals or mixtures thereof. In some embodiments, a metaloxide surface is a native oxide formed on a metallic material.

In some embodiments, the second surface may comprise a metal surfaceincluding a passivation block layer thereover. That is, in someembodiments, the second surface may comprise a metal surface comprisinga material that inhibits deposition of the passivation layer thereover,for example a self-assembled monolayer (SAM).

In some embodiments, an organic passivation material is selectivelydeposited on a first metal oxide surface, which is an oxidized surfaceof metallic material, relative to a second dielectric surface

In some embodiments, one of the first and second surfaces is a metal ormetallic surface of a substrate and the other surface is a dielectricsurface of the substrate. The term dielectric is used in the descriptionherein for the sake of simplicity in distinguishing from the othersurface, namely the metal or metallic surface. It will be understood bythe skilled artisan that not all non-conducting surfaces are dielectricsurfaces, and conversely not all metallic surfaces are conducting. Forexample, the metal or metallic surface may comprise an oxidized metalsurface that is electrically non-conducting or has a very highresistivity. Selective deposition processes taught herein can deposit onsuch non-conductive metallic surfaces with minimal deposition onpassivated dielectric surfaces and similarly selective depositionprocesses can deposit on dielectric surfaces with minimal deposition onpassivated non-conductive metallic surfaces.

In some embodiments, the substrate may be pretreated or cleaned prior toor at the beginning of the selective deposition process. In someembodiments, the substrate may be subjected to a plasma cleaning processat prior to or at the beginning of the selective deposition process. Insome embodiments, a plasma cleaning process may not include ionbombardment, or may include relatively small amounts of ion bombardment.For example, in some embodiments the substrate surfaces may be exposedto plasma, radicals, excited species, and/or atomic species prior to orat the beginning of the selective passivation layer deposition process.In some embodiments, the substrate surface may be exposed to hydrogenplasma, radicals, or atomic species prior to or at the beginning of theselective passivation layer deposition process.

In some embodiments a non-plasma pretreatment process is conducted. Forexample, in some embodiments the substrate surface may be exposed to asilicon reactant, such as N-(trimethylsilyl)dimethylamine (TMSDMA) ortrimethylchlorosilane. The reactant may be provided in a single longpulse, or in a sequence of multiple shorter pulses. In some embodimentsthe reactant is provided in 1 to 25 pulses of from about 1 to about 60seconds. In between pulses, the reaction chamber may be purged with aninert gas. The purge may be, for example for about 1 to 30 seconds.

In some embodiments the surface is contacted with an alkylaminosilanehaving the formula (R^(I))₃Si(NR^(II)R^(III)), wherein R^(I) is a linearor branched C1-C5 alkyl group or a linear or branched C1-C4 alkyl group,R^(II) is a linear or branched C1-C5 alkyl group, a linear or branchedC1-C4 alkyl group, or hydrogen, and R^(III) is a linear or branchedC1-C5 alkyl group or a linear or branched C1-C4 alkyl group.

In some embodiments the surface is contacted with a silane having thegeneral formula (R^(I))₃SiA, wherein R^(I) is a linear or branched C1-C5alkyl group or a linear or branched C1-C4 alkyl group, and A is anyligand which is reactive with the silicon containing surface. That is,the silane bonds to the surface through ligand A, or ligand A forms anbond to the surface but then ligand A may migrate away from the surfaceand/or silane.

The temperature of the pretreatment process may be, for example, fromabout 100 to about 300° C. The pressure during the pretreatment processmay be, for example, from about 10⁻⁵ to about 760 Torr, or in someembodiments from about 1 to 10 Torr or about 0.1 to about 10 Torr. Insome embodiments, a pretreatment or cleaning process may be carried outin situ, that is in the same reaction chamber as a selective depositionprocess. However in some embodiments a pretreatment or cleaning processmay be carried out in a separate reaction chamber. In some embodimentsthe reaction chamber in which the pretreatment process is carried out ispart of a cluster tool, including one or more additional reactionchambers. For example, such a cluster tool may include additionalreaction chambers for the deposition of the inhibitor, etching and/ordeposition of the film of interest. In some embodiments a cluster toolincludes separate modules for pretreatment, inhibitor deposition, plasmacleaning (etch) post-deposition of the inhibitor, deposition of thelayer of interest and plasma post-deposition cleaning. In someembodiments the same module can be used for two or more processes. Forexample, the same module may be used for pretreatment, plasma cleaningafter deposition of the inhibitor and after deposition of the layer ofinterest. In some embodiments a cluster tool comprises a firstpretreatment module, a plasma cleaning module, an inhibitor depositionmodule, and a module for depositing the layer of interest.

Selectivity

The skilled artisan will appreciate that selective deposition can befully selective or partially selective. A partially selective processcan result in fully selective layer by a post-deposition etch thatremoves all of the deposited material from over surface B withoutremoving all of the deposited material from over surface A. Because asimple etch back process can leave a fully selective structure withoutthe need for expensive masking processes, the selective deposition neednot be fully selective in order to obtain the desired benefits.

Selectivity of deposition on surface A relative to surface B can begiven as a percentage calculated by [(deposition on surfaceA)-(deposition on surface B)]/(deposition on the surface A). Depositioncan be measured in any of a variety of ways. For example, deposition maybe given as the measured thickness of the deposited material, or may begiven as the measured amount of material deposited. In embodimentsdescribed herein, selective deposition of an organic passivation layercan be conducted on a first surface (A) relative to a second surface(B). Subsequently, a layer of interest is selectively deposited on thesecond surface (A) relative to the organic passivation layer (B) overthe first surface.

In some embodiments, selectivity for the selective deposition of thepassivation layer on the first surface (relative to the second surface)and/or selectivity of the layer of interest on the second surface(relative to the passivation layer on the first surface) is greater thanabout 10%, greater than about 50%, greater than about 75%, greater thanabout 85%, greater than about 90%, greater than about 93%, greater thanabout 95%, greater than about 98%, greater than about 99% or evengreater than about 99.5%. In embodiments described herein, theselectivity for the organic passivation layer deposition can change overthe duration or thickness of a deposition. Surprisingly, selectivity hasbeen found to increase with the duration of the deposition for the vaporphase polymer layer depositions described herein. In contrast, typicalselective deposition based on differential nucleation on differentsurfaces tends to become less selective with greater duration orthickness of a deposition.

In some embodiments, deposition only occurs on the first surface anddoes not occur on the second surface. In some embodiments, deposition onsurface A of the substrate relative to surface B of the substrate is atleast about 80% selective, which may be selective enough for someparticular applications. In some embodiments, the deposition on thesurface A of the substrate relative to surface B of the substrate is atleast about 50% selective, which may be selective enough for someparticular applications. In some embodiments the deposition on surface Aof the substrate relative to the surface B of the substrate is at leastabout 10% selective, which may be selective enough for some particularapplications. The skilled artisan will appreciate that a partiallyselective process can result in fully selective structure layer by apost-deposition etch that removes all of the deposited material fromover surface B without removing all of the deposited material from oversurface A. Furthermore, the post-deposition etch can also aid intailoring the position and/or profile of the selectively depositedlayer, as will be better understood from the description of FIGS. 17-23Bbelow.

In some embodiments, the organic layer deposited on the first surface ofthe substrate may have a thickness less than about 50 nm, less thanabout 20 nm, less than about 10 nm, less than about 5 nm, less thanabout 3 nm, less than about 2 nm, or less than about 1 nm, while a ratioof material deposited on the first surface of the substrate relative tothe second surface of the substrate may be greater than or equal toabout 200:1, greater than or equal to about 100:1, greater than or equalto about 50:1, greater than or equal to about 25:1, greater than orequal to about 20:1, greater than or equal to about 15:1, greater thanor equal to about 10:1, greater than or equal to about 5:1, greater thanor equal to about 3:1, or greater than or equal to about 2:1.

In some embodiments the selectivity of the selective depositionprocesses described herein may depend on the material compositions ofthe materials which define the first and/or second surface of thesubstrate. For example, in some embodiments where the first surfacecomprises a BTA passivated Cu surface and the second surface comprises anatural or chemical silicon dioxide surface the selectivity may begreater than about 8:1 or greater than about 15:1. In some embodiments,where the first surface comprises a metal or metal oxide and the secondsurface comprises a natural or chemical silicon dioxide surface theselectivity may be greater than about 5:1 or greater than about 10:1.

Selective Deposition on Dielectric

FIGS. 1A-1D schematically illustrate a first embodiment for selectivepassivation of a first surface relative to a second surface, followed byselective deposition on the second surface relative to the passivatedfirst surface. In the illustrated embodiment, the first surfacecomprises a metallic material; the second surface comprises an inorganicdielectric material; and the material of interest deposited on thesecond surface comprises a dielectric material.

FIG. 1A illustrates a substrate having materially different surfacesexposed. For example, the first surface can comprise or be defined by ametal, such as cobalt (Co), copper (Cu), tungsten (W) or molybdenum(Mo). The second surface can comprise or be defined by an inorganicdielectric, such as a low-k layer (typically a silicon oxide-basedlayer) or a silicon surface having native oxide (also a form of siliconoxide) formed thereover.

FIG. 1B shows the substrate of FIG. 1A after selective deposition of apassivation layer over the first surface. For example, the passivationlayer may be a polymer layer deposited selectively on the metallicsurface of the first layer. Methods for selectively depositing polymerlayers by vapor deposition techniques are disclosed in U.S. patentapplication Ser. No. 15/170,769, filed Jun. 1, 2016, the entiredisclosure of which is incorporated herein by references for allpurposes. Further information and examples of selective deposition ofpolymer layers to serve as the passivation layer are provided below.

In some embodiments, the selectively deposited polymer is a polyimide.In some embodiments, the polymer deposited is a polyamide. Otherexamples of deposited polymers include dimers, trimers, polyurea layers,polythiophene polyurethanes, polythioureas, polyesters, polyimines,other polymeric forms or mixtures of the above materials. Vapordeposited organic materials include polyamic acid, which may be aprecursor to polymer formation. The selectively deposited layer can be amixture including polymer and polyamic acid, which for purposes of thepresent disclosure will be considered to be a polymer.

In some embodiments, selective deposition of the polymer, such as apolyimide, on the first metal-comprising surface, such as a Cu surface,occurs at a growth rate of about 0.5 Å/cycle to about 20 Å/cycle, about1 Å/cycle to about 15 Å/cycle, about 1.5 Å/cycle to about 10 Å/cycle, orabout 2 Å/cycle to about 8 Å/cycle. In some embodiments the growth rateof the polymer, such as a polyimide, on the first metal-comprisingsurfaces, such as Cu, is more than about 0.5 Å/cycle, more than about 1Å/cycle, more than about 3 Å/cycle, more than about 5 Å/cycle while onthe upper end the growth rate in some embodiments is less than about 20Å/cycle, less than about 15 Å/cycle, less than about 10 Å/cycle or lessthan about 8 Å/cycle. Selectivity is maintained at these growth rates insome embodiments.

In some embodiments, selective deposition of a polyimide on Cu surfacesoccurs at a growth rate of about 0.5 Å/cycle to about 20 Å/cycle, about1 Å/cycle to about 15 Å/cycle, about 1.5 Å/cycle to about 10 Å/cycle, orabout 2 Å/cycle to about 8 Å/cycle. In some embodiments the growth rateof the polyimide on the Cu surfaces is more than about 0.5 Å/cycle, morethan about 1 Å/cycle, more than about 3 Å/cycle, more than about 5Å/cycle while on the upper end the growth rate in some embodiments isless than about 20 Å/cycle, less than about 15 Å/cycle, less than about10 Å/cycle or less than about 8 Å/cycle. Selectivity is maintained atthese growth rates in some embodiments.

As noted above, any organic material deposited on the second surface (aninorganic dielectric surface in this example) can be removed by an etchback process. In some embodiments, an etch process subsequent toselective deposition of the organic layer may remove deposited organicmaterial from both the first surface and the second surface of thesubstrate. In some embodiments the etch process may be isotropic.

In some embodiments, the etch process may remove the same amount, orthickness, of material from the first and second surfaces. That is, insome embodiments the etch rate of the organic material deposited on thefirst surface may be substantially similar to the etch rate of theorganic material deposited on the second surface. Due to the selectivenature of the deposition processes described herein, the amount oforganic material deposited on the second surface of the substrate issubstantially less than the amount of material deposited on the firstsurface of the substrate. Therefore, an etch process may completelyremove deposited organic material from the second surface of thesubstrate while deposited organic material may remain on the firstsurface of the substrate. Suitable processes for etching polymers aredescribed below with respect to FIG. 1D.

FIG. 1C shows the substrate of FIG. 1B following selective deposition ofa layer of interest X on the second surface (an inorganic dielectricsurface in this example) relative to the passivation layer on the firstsurface (a metallic surface in this example). The layer of interest Xcan be a dielectric material, such as a metal oxide such as zirconiumoxide, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide,yttrium oxide, lanthanum oxide, or other transition metal oxide ormixtures thereof. In some embodiments the metal oxide is a dielectrictransition metal oxide, or mixture of dielectric transition metaloxides. In some embodiments the layer of interest X can be a metalnitride, such as titanium nitride. Methods for selectively depositingsuch metal oxide layers by vapor deposition techniques, employinghydrophobic precursors to aid selectivity relative to organicpassivation layers, are disclosed in U.S. provisional patent applicationNo. 62/332,396, filed May 5, 2016, the entire disclosure of which isincorporated herein by references for all purposes. Further informationand examples of selective deposition of metal oxide and other layers ofinterest are provided below.

As noted above, any X material deposited on the passivation layer overthe first surface can be removed by an etch back process. Because thelayer of interest is deposited selectively on the second surface, any Xmaterial left on the passivation surface will be thinner than thepassivation layer formed on the metallic surface. Accordingly, the etchback process can be controlled to remove all of the X material over thepassivation layer without removing all of the layer of interest fromover the dielectric surface. Repeatedly depositing selectively andetching back in this manner can result in an increasing thickness of theX material on the dielectric with each cycle of deposition and etch.Repeatedly depositing selectively and etching back in this manner canalso result in increased overall selectivity of the X material on thedielectric, as each cycle of deposition and etch leaves a cleanpassivation layer over which the selective X deposition nucleatespoorly. Alternatively, any X material can be removed during subsequentremoval of the passivation layer, example conditions for which aredescribed with respect to FIG. 1D below, in a lift-off process. As isknown in the art, a lift-off process removes an overlying material byundercutting with removal of an underlying material. Any X materialformed on the passivation layer in a short selective deposition processtends to be noncontinuous, allowing access of the etchant to theunderlying material to be removed. The lift-off etch need not fullyremove the passivation layer in order to remove all of the undesired Xmaterial from the passivation layer surface, such that either a directetch or the lift-off method can be used to remove the X material fromthe passivation layer surface in a cyclical selective deposition andremoval.

FIG. 1D shows the substrate of FIG. 1C after removal of the passivationlayer from the first surface. In some embodiments, the etch process maycomprise exposing the substrate to a plasma. In some embodiments, theplasma may comprise oxygen atoms, oxygen radicals, oxygen plasma, orcombinations thereof. In some embodiments, the plasma may comprisehydrogen atoms, hydrogen radicals, hydrogen plasma, or combinationsthereof (see, e.g., Example 2 for selective deposition of passivationlayer below). In some embodiments, the plasma may also comprise noblegas species, for example Ar or He species. In some embodiments theplasma may consist essentially of noble gas species. In some instances,the plasma may comprise other species, for example nitrogen atoms,nitrogen radicals, nitrogen plasma, or combinations thereof. In someembodiments, the etch process may comprise exposing the substrate to anetchant comprising oxygen, for example O₃. In some embodiments, thesubstrate may be exposed to an etchant at a temperature of between about30° C. and about 500° C., or between about 100° C. and about 400° C. Insome embodiments, the etchant may be supplied in one continuous pulse ormay be supplied in multiple shorter pulses. As noted above, thepassivation layer removal can be used to lift-off any remaining Xmaterial from over the passivation layer, either in a complete removalof the passivation layer or in a partial removal of the passivationlayer in a cyclical selective deposition and removal.

As noted above, in some embodiments, O₃ (e.g. O₃/N₂) can be used in theetch process for removal of the organic passivation layer. In someembodiments, the etch process may be performed at a substratetemperature of about 20° C. to about 500° C. In some embodiments, theetch process may be performed at a substrate temperature of about 50° C.to about 300° C. In some embodiments, the etch process may be performedat a substrate temperature of about 100° C. to about 250° C. In someembodiments, the etch process may be performed at a substratetemperature of about 125° C. to about 200 C. In some embodiments, theetch process may be performed at a rate of about 0.05 nm/min to about50.0 nm/min. In some embodiments, the etch process may be performed at arate of about 0.1 nm/min to about 5.0 nm/min. In some embodiments, theetch process may be performed at a rate of about 0.2 nm/min to about 2.5nm/min. In some embodiments for single wafer or small batch (e.g., 5wafers or less) processing, a low O₃ concentration etch process may beused, wherein the low O₃ concentration etch process is performed at 0.01Torr to 200 Torr, or about 0.1 Torr to 100 Torr (e.g., 2 Torr). Etchantpulsing can be between 0.01 sec and 20 seconds, between 0.05 sec and 10sec, or between 0.1 sec and 2 seconds (e.g., 0.5 sec pulse/0.5 sec purgeof O₃). O₃ flow can range from 0.01 slm to 1 slm, or from 0.01 slm to0.250 slm. Inert (e.g., N₂) carrier gas flow of can range from 0.1 slmto 20 slm, or from 0.5 slm to 5 slm (e.g., 1.2 slm). In someembodiments, a high O₃ concentration etch process may be used, whereinthe high O₃ concentration etch process is performed at 1-100 Torr, or5-20 Torr (e.g., 9 Torr), with longer exposures per cycle. For example,O₃ exposure times can be between 0.1 sec and 20 s, or between 0.5 secand 5 seconds (e.g., 1 sec pulse/1 sec purge of O₃). O₃ flow for suchhigh O₃ concentration processes can be between 0.1 slm and 2.0 slm, orbetween 0.5 slm and 1.5 slm (e.g, 750 sccm), with an inert (e.g., N₂)dilution flow of 0.1 slm to 20 slm, or 0.5 slm to 5 slm (e.g., 1.2 slm).

In some embodiments a bake step can be carried out after etching. Thebake may be carried out in the same reactor as the deposition of theorganic material, the same reactor as the etch process, the same reactorin which a layer of interest is to be subsequently deposited, or may becarried out in a separate reactor from one or more of those aspects ofthe process. In some embodiments the bake process is carried out in areaction chamber that is part of a cluster tool and the substrate ismoved to one or more different reaction chambers of the cluster tool foradditional processing after the bake.

In some embodiments the substrate is baked for a period of about 1 toabout 15 minutes. In some embodiments the substrate is baked at atemperature of about 200 to about 500° C. In some embodiments the bakestep comprises two or more steps in which the substrate is baked for afirst period of time at a first temperature and then baked for a secondperiod of time at a second temperature.

Additional treatments, such as heat or chemical treatment, can beconducted prior to, after or between the foregoing processes. Forexample, treatments may modify the surfaces or remove portions of themetal, silicon oxide, polymer passivation and metal oxide surfacesexposed at various stages of the process. In some embodiments thesubstrate may be pretreated or cleaned prior to or at the beginning ofthe selective deposition process. In some embodiments, the substrate maybe subjected to a plasma cleaning process at prior to or at thebeginning of the selective deposition process. In some embodiments, aplasma cleaning process may not include ion bombardment, or may includerelatively small amounts of ion bombardment. For example, in someembodiments the substrate surface may be exposed to plasma, radicals,excited species, and/or atomic species prior to or at the beginning ofthe selective deposition process. In some embodiments, the substratesurface may be exposed to hydrogen plasma, radicals, or atomic speciesprior to or at the beginning of the selective deposition process. Insome embodiments, a pretreatment or cleaning process may be carried outin the same reaction chamber as a selective deposition process, howeverin some embodiments a pretreatment or cleaning process may be carriedout in a separate reaction chamber.

Selective Deposition on Metal

FIGS. 2A-2E illustrate schematically illustrate a second embodiment forselective passivation of a first surface relative to a second surface,followed by selective deposition on the second surface relative to thepassivated first surface. In the illustrated embodiment, the firstsurface comprises an inorganic dielectric material; the second surfacecomprises a metallic surface; and the material of interest deposited onthe second surface comprises a dielectric material or a metal.

FIG. 2A illustrates a substrate similar to that of FIG. 1A, havingmaterially different surfaces. For this embodiment, however, thesurfaces are described with reversed terminology. In particular, thesecond surface can comprise or be defined by a metallic material, suchas cobalt (Co), copper (Cu), tungsten (W) or molybdenum (Mo). The firstsurface can comprise an inorganic dielectric, such as a low-k layer(typically a silicon oxide-based layer) or a silicon surface havingnative oxide (also a form of silicon oxide) formed thereover. Apassivation blocking layer is formed over the second surface. Note thatthe term “blocking” is not meant to imply that the subsequent selectivedeposition of a passivation layer is completely blocked by thepassivation blocking layer. Rather, the passivation blocking layer overthe second surface need only inhibit the deposition of the passivationlayer to have a lower growth rate relative to the growth rate over thefirst surface.

In one embodiment, the passivation blocking layer comprises aself-assembled monolayer (SAM). A SAM can be selectively formed over thesecond (metallic) surface without forming on the first (dielectric)surface. Advantageously, sulfur-containing SAM has been found effectiveto minimize deposition of the passivation layer thereover.

FIG. 2B shows the selective formation of a passivation layer (e.g.,organic passivation layer) over the first surface, in this case theinorganic dielectric layer, relative to the passivation blocking layerover the second surface. As noted in the above incorporated patentapplication Ser. No. 15/170,769, filed Jun. 1, 2016, vapor depositionprocesses described therein are capable of depositing polymer oninorganic dielectrics, and can even deposit selectively (i.e., atdifferential deposition rates) over different types of silicon oxide. Inthe present embodiment, sulfur-containing SAM inhibits the polymerdeposition thereover, such that polymer can selectively form over thefirst surface, and can serve as a passivation layer against a subsequentdeposition.

FIG. 2C shows the substrate of FIG. 2B after removal of the passivationblocking layer from over the second surface. For example,sulfur-containing SAM material can be removed by heat treatment attemperatures lower than those that would remove a polymer layer likepolyimide. Accordingly, a passivation layer is left selectively over thefirst surface, while the second surface is exposed. The structure issimilar to that of FIG. 1B except that the first passivated surface isan inorganic dielectric in this embodiment, and the second surface is ametallic surface.

FIG. 2D shows the substrate of FIG. 2C after selective deposition of alayer of interest X on the second surface relative to the passivationlayer over the first surface. As noted with respect to the firstembodiment, and described in the above-incorporated provisional patentapplication No. 62/332,396, filed May 5, 2016, metal oxides can beselectively deposited using vapor deposition techniques and hydrophobicprecursors to aid selectivity relative to organic passivation layers, ona number of different surfaces. Further information and examples ofselective deposition of metal oxide and other layers of interest areprovided below.

Alternatively, the layer of interest X is a metal layer. U.S. Pat. No.8,956,971, issued Feb. 17, 2015 and U.S. Pat. No. 9,112,003, issued Aug.18, 2015, the entire disclosures of which are incorporated herein byreference for all purposes, teach processes for selective deposition ofmetallic materials on metallic surfaces, relative to other materialsurfaces, including organic surfaces.

FIG. 2E shows the substrate of FIG. 2D after removal of the passivationlayer from the first surface, leaving a selectively formed dielectric onmetal or metal on metal. The passivation layer can be removed asdescribed above with respect to the first embodiment, such as by O₃etching.

FIGS. 3A-3B illustrate a third embodiment for selective passivation of afirst surface relative to a second surface, followed by selectivedeposition on the second surface relative to the passivated firstsurface. In the illustrated embodiment, the process of FIGS. 2A-2D isfirst conducted.

FIG. 3A shows the substrate of FIG. 2D after a further selectivedeposition. In the event the layer of interest X is a metallic material,the further selective deposition can form a dielectric material as asecond layer of interest Y over the first layer of interest, selectivelyrelative to the organic passivation layer. As noted above with respectto the first and second embodiments, and described in theabove-incorporated provisional patent application No. 62/332,396, filedMay 5, 2016, metal oxides can be selectively deposited using vapordeposition techniques and hydrophobic precursors to aid selectivityrelative to organic passivation layers, on a number of differentsurfaces. Further information and examples of selective deposition ofmetal oxide and other layers of interest are provided below.

FIG. 3B shows the substrate of FIG. 3A after removal of the passivationlayer from the first surface, leaving a selectively formed dielectric onmetal. The passivation layer can be removed as described above withrespect to the first embodiment, such as by O₃ etching.

The second and third embodiments, like the first embodiment, can involveadditional treatments, such as heat or chemical treatment, conductedprior to, after or between the foregoing processes.

Selective Deposition of Passivation Layer

As disclosed in the incorporated U.S. patent application Ser. No.15/170,769, filed Jun. 1, 2016, vapor phase deposition techniques can beapplied to organic passivation layers and polymers such as polyimidelayers, polyamide layers, polyuria layers, polyurethane layers,polythiophene layers, and more. CVD of polymer layers can producegreater thickness control, mechanical flexibility, conformal coverage,and biocompatibility as compared to the application of liquid precursor.Sequential deposition processing of polymers can produce high growthrates in small research scale reactors. Similar to CVD, sequentialdeposition processes can produce greater thickness control, mechanicalflexibility, and conformality. The terms “sequential deposition” and“cyclical deposition” are employed herein to apply to processes in whichthe substrate is alternately or sequentially exposed to differentprecursors, regardless of whether the reaction mechanisms resemble ALD,CVD, MLD or hybrids thereof.

Referring to FIG. 4A and in some embodiments, a substrate comprising afirst surface and a second surface is provided at block 11. The firstand second surfaces may have different material properties as discussedherein. In some embodiments, the first surface may be a conductivesurface, for example a metal or metallic surface, and the second surfacemay be a dielectric surface (see, e.g., FIGS. 1A-1D). In someembodiments, the first surface may be a dielectric surface and thesecond surface may be a second, different dielectric surface. In someembodiments, the first surface may be a dielectric surface, for examplea silicon oxide-based material, and the second surface may be apassivation blocking material such as an SAM (see, e.g., FIGS. 2A-3B).

In some embodiments, the first precursor may be vaporized at a firsttemperature to form the first vapor phase precursor. In someembodiments, the first precursor vapor is transported to the substratethrough a gas line at a second temperature. In some embodiments, thesecond transportation temperature is higher than the first vaporizationtemperature. In some embodiments, the substrate is contacted with afirst vapor phase precursor, or reactant, at block 12 for a firstexposure period. In some embodiments, the substrate may be contactedwith the first vapor phase precursor at a third temperature that ishigher than the first temperature.

In some embodiments, the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In some embodiments, the substrate is contacted with a second vaporphase precursor, or reactant, at block 13 for a second exposure period.In some embodiments, the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor. In someembodiments, the second reactant vapor is transported to the substratethrough a gas line at a second temperature. In some embodiments, thefifth transportation temperature is higher than the first vaporizationtemperature. In some embodiments, the substrate may be contacted withthe second vapor phase precursor at a sixth temperature that is higherthan the fourth temperature. In some embodiments, the sixth temperaturemay be substantially the same as the third temperature at which thefirst vapor phase precursor contacts the substrate.

In some embodiments, the second precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments, where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In block 14 an organic layer is selectively deposited on the firstsurface relative to the second surface. The skilled artisan willappreciate that selective deposition of an organic layer is the resultof the above-described contacting actions, 12-13, rather than a separateaction. In some embodiments, the above-described contacting actions,blocks 12-13, may be considered a deposition cycle. Such a selectivedeposition cycle can be repeated until a layer of sufficient thicknessis left on the substrate (block 15) and the deposition is ended (block16). The selective deposition cycle can include additional acts, neednot be in the same sequence nor identically performed in eachrepetition, and can be readily extended to more complex vapor depositiontechniques. For example, a selective deposition cycle can includeadditional reactant supply processes, such as the supply and removal(relative to the substrate) of additional reactants in each cycle or inselected cycles. Though not shown, the process may additionally comprisetreating the deposited layer to form a polymer (for example, UVtreatment, annealing, etc.). The selectively formed organic layer canserve as a passivation layer to inhibit deposition thereover andincrease selectivity in a subsequent selective deposition of a layer ofinterest, as noted above

Referring to FIG. 4B, the vapor deposition process of FIG. 4A may insome embodiments comprise an atomic layer deposition process. Asubstrate comprising a first surface and a second surface is provided atblock 21. The first and second surfaces may have different materialproperties. In some embodiments, the first surface may be a conductivesurface, for example a metal or metallic surface, and the second surfacemay be a dielectric surface (see, e.g., FIGS. 1A-1D). In someembodiments, the first surface may be a dielectric surface and thesecond surface may be a second, different dielectric surface. In someembodiments, the first surface may be a dielectric surface, for examplea silicon oxide-based material, and the second surface may be apassivation blocking material such as an SAM (see, e.g., FIGS. 2A-3B).

In some embodiments a sequential deposition method for selective vapordeposition of an organic passivation layer comprises vaporizing a firstorganic precursor is at a first temperature to form a first precursorvapor at block 22. In some embodiments, the first precursor vapor istransported to the substrate through a gas line at a second temperature.In some embodiments the second transportation temperature is higher thanthe first vaporization temperature. In some embodiments, the substrateis contacted with the vapor phase first precursor for a first exposureperiod at block 23. In some embodiments, the first precursor, or speciesthereof, chemically adsorbs on the substrate in a self-saturating orself-limiting fashion. The gas line can be any conduit that transportsthe first precursor vapor from the source to the substrate. In someembodiments, the substrate may be exposed to the first precursor vaporat a third temperature that is higher than the first temperature.

In some embodiments the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments, where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

Excess of the first precursor vapor (and any volatile reactionby-products) may then be removed from contact with the substrate atblock 24. Such removal can be accomplished by, for example, purging,pump down, moving the substrate away from a chamber or zone in which itis exposed to the first reactant, or combinations thereof. In someembodiments, a first precursor removal period, for example a purgeperiod, is from about 0.01 seconds to about 60 seconds, about 0.05seconds to about 30 seconds, about 0.1 seconds to about 10 seconds orabout 0.2 seconds to about 5 seconds. The optimum removal period can bereadily determined by the skilled artisan based on the particularcircumstances. In some embodiments, where batch reactors may be used,removal periods of greater than 60 seconds may be employed.

In some embodiments, the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor at block 25. Insome embodiments, the second reactant vapor is transported to thesubstrate through a gas line at a second temperature. In someembodiments, the fifth transportation temperature is higher than thefirst vaporization temperature. In some embodiments, the substrate maybe contacted with the second vapor phase precursor at a sixthtemperature that is higher than the fourth temperature. In someembodiments, the sixth temperature may be substantially the same as thethird temperature at which the first vapor phase precursor contacts thesubstrate. In some embodiments, the substrate may be exposed to a secondprecursor vapor for a second exposure period at block 26. In someembodiments, the second reactant may react with the adsorbed species ofthe first reactant on the substrate.

In some embodiments, the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments, where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In some embodiments, excess of the second precursor vapor (and anyvolatile reaction by-product) is removed from contact with the substrateat block 27, such that the first reactant vapor and the second reactantvapor do not mix. In some embodiments, the vapor deposition process ofthe organic layer does not employ plasma and/or radicals, and can beconsidered a thermal vapor deposition process. In some embodiments, asecond precursor removal period, for example a purge period, is fromabout 0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum removal period can be readily determined bythe skilled artisan based on the particular circumstances. In someembodiments, where batch reactors may be used, removal periods ofgreater than 60 seconds may be employed.

In block 28 an organic layer is selectively deposited on the firstsurface relative to the second surface. The skilled artisan willappreciate that selective deposition of an organic layer is the resultof the above-described contacting actions rather than a separate action.In some embodiments, the above-described contacting and removing (and/orhalting supply) actions, blocks 23-27, may be considered a depositioncycle. In some embodiments, a deposition cycle may be repeated until anorganic layer of a desired thickness is selectively deposited. Such aselective deposition cycle can be repeated (block 29) until a layer ofsufficient thickness is left on the substrate and the deposition isended (block 30). The selective deposition cycle can include additionalacts, need not be in the same sequence nor identically performed in eachrepetition, and can be readily extended to more complex vapor depositiontechniques. For example, a selective deposition cycle can includeadditional reactant supply processes, such as the supply and removal ofadditional reactants in each cycle or in selected cycles. Though notshown, the process may additionally comprise treating the depositedlayer to form a polymer (for example, UV treatment, annealing, etc.).

Various reactants can be used for the above described processes. Forexample, in some embodiments, the first precursor or reactant is anorganic reactant such as a diamine, e.g., 1,6-diaminohexane (DAH), orany other monomer with two reactive groups. In some embodiments, thesecond reactant or precursor is also an organic reactant capable ofreacting with adsorbed species of the first reactant under thedeposition conditions. For example, the second reactant can be ananhydride, such as furan-2,5-dione (maleic acid anhydride). Theanhydride can comprise a dianhydride, e.g., pyromellitic dianhydride(PMDA), or any other monomer with two reactive groups which will reactwith the first reactant.

In some embodiments the substrate is contacted with the first precursorprior to being contacted with the second precursor. Thus, in someembodiments the substrate is contacted with an amine, such as a diamine,for example 1,6-diaminohexane (DAH) prior to being contacted withanother precursor. However, in some embodiments the substrate may becontacted with the second precursor prior to being contacted with thefirst precursor. Thus, in some embodiments the substrate is contactedwith an anhydride, such as furan-2,5-dione (maleic acid anhydride), or adianhydride, e.g., pyromellitic dianhydride (PMDA) prior to beingcontacted with another precursor.

In some embodiments, different reactants can be used to tune the layerproperties. For example, a polyimide layer could be deposited using4,4′-oxydianiline or 1,4-diaminobenzene instead of 1,6-diaminohexane toget a more rigid structure with more aromaticity and increased dry etchresistance.

In some embodiments, the reactants do not contain metal atoms. In someembodiments, the reactants do not contain semimetal atoms. In someembodiments, one of the reactants comprises metal or semimetal atoms. Insome embodiments, the reactants contain carbon and hydrogen and one ormore of the following elements: N, O, S, P or a halide, such as Cl or F.In some embodiments, the first reactant may comprise, for example,adipoyl chloride (AC).

Deposition conditions can differ depending upon the selected reactantsand can be optimized upon selection. In some embodiments, the reactiontemperature can be selected from the range of about 80° C. to about 250°C. In some embodiments, the reaction chamber pressure may be from about1 mTorr to about 1000 Torr, from about 10-5 to about 760 Torr, or insome embodiments from about 1 to 10 Torr. In some embodiments, forexample where the selectively deposited organic layer comprisespolyamide, the reaction temperature can be selected from a range ofabout 80° C. to about 150° C. In some embodiments where the selectivelydeposited organic layer comprises polyamide, the reaction temperaturemay be greater than about 80° C., 90° C., 100° C., 110° C., 120° C.,130° C., 140° C., or 150° C. In some embodiments where the selectivelydeposited organic layer comprises polyimide, the reaction temperaturemay be greater than about 160° C., 180° C., 190° C., 200° C., or 210° C.

For example, for sequential deposition of polyimide using PMDA and DAHin a single wafer deposition tool, substrate temperatures can beselected from the range of about 150° C. to about 250° C., or from about170° C. to about 210° C., and pressures can be selected from the rangeof about 1 mTorr to about 760 Torr, or between about 100 mTorr to about100 Torr.

In some embodiments reactants for use in the selective depositionprocesses described herein may have the general formula:

R¹(NH₂)₂  (1)

wherein R¹ may be an aliphatic carbon chain comprising 1-5 carbon atoms,2-5 carbon atoms, 2-4 carbon atoms, 5 or fewer carbon atoms, 4 or fewercarbon atoms, 3 or fewer carbon atoms, or 2 carbon atoms. In someembodiments, the bonds between carbon atoms in the reactant or precursormay be single bonds, double bonds, triple bonds, or some combinationthereof. Thus, in some embodiments a reactant may comprise two aminogroups. In some embodiments, the amino groups of a reactant may occupyone or both terminal positions on an aliphatic carbon chain. However, insome embodiments the amino groups of a reactant may not occupy eitherterminal position on an aliphatic carbon chain. In some embodiments, areactant may comprise a diamine. In some embodiments, a reactant maycomprise an organic precursor selected from the group of1,2-diaminoethane (1), 1,3-diaminopropane (1), 1,4-diaminobutane(1),1,5-diaminopentane (1), 1,2-diaminopropane (1), 2,3-butanediamine,2,2-dimethyl-1,3-propanediamine (1).

In some embodiments, reactants for use in the selective depositionprocesses described herein may have the general formula:

R²(COCl)₂  (2)

wherein R² may be an aliphatic carbon chain comprising 1-3 carbon atoms,2-3 carbon atoms, or 3 or fewer carbon atoms. In some embodiments, thebonds between carbon atoms in the reactant or precursor may be singlebonds, double bonds, triple bonds, or some combination thereof. In someembodiments, a reactant may comprise a chloride. In some embodiments, areactant may comprise a diacyl chloride. In some embodiments, a reactantmay comprise an organic precursor selected from the group of oxalylchloride (I), malonyl chloride, and fumaryl chloride.

In some embodiments, a reactant comprises an organic precursor selectedfrom the group of 1,4-diisocyanatobutane or 1,4-diisocyanatobenzene. Insome embodiments, a reactant comprises an organic precursor selectedfrom the group of terephthaloyl dichloride, alkyldioyl dichlorides, suchas hexanedioyl dichloride, octanedioyl dichloride, nonanedioyldichloride, decanedioyl dichloride, or terephthaloyl dichloride. In someembodiments, a reactant comprises an organic precursor selected from thegroup of 1,4-diisothiocyanatobenzene or terephthalaldehyde. In someembodiments, a reactant being vaporized can be also a diamine, such as1,4-diaminobenzene, decane-1,10-diamine, 4-nitrobenzene-1,3-diamine,4,4′-oxydianiline, or ethylene diamine. In some embodiments, a reactantcan be a terephthalic acid bis(2-hydroxyethyl) ester. In someembodiments, a reactant can be a carboxylic acid, for example alkyl-,alkenyl-, alkadienyl-dicarboxylic or tricarboxylic acid, such asethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acidor propane-1,2,3-tricarboxylic acid. In some embodiments, a reactant canbe an aromatic carboxylic or dicarboxylic acid, such as benzoic acid,benzene-1,2-dicarboxylic acid, benzene-1,4-dicarboxylic acid orbenzene-1,3-dicarboxylic acid. In some embodiments, a reactant maycomprise one or more OH-groups bonded to a hydrocarbon. In someembodiments, a reactant can be selected from the group of diols, triols,aminophenols such as 4-aminophenol, benzene-1,4-diol orbenzene-1,3,5-triol. In some embodiments, a reactant can be8-quinolinol. In some embodiments, the reactant can comprisealkenylchlorosilanes, like alkenyltrichlorosilanes, such as7-octenyltrichlorosilane.

In some embodiments, a reactant may have a vapor pressure greater thanabout 0.5 Torr, 0.1 Torr, 0.2 Torr, 0.5 Torr, 1 Torr or greater at atemperature of about 20° C. or room temperature. In some embodiments, areactant may have a boiling point less than about 400° C., less than300° C., less than about 250° C., less than about 200° C., less thanabout 175° C., less than about 150° C., or less than about 100° C.

Selective Deposition of Layers of Interest Relative to Organic Surfaces

As disclosed in the incorporated U.S. provisional patent application No.62/332,396, filed May 5, 2016, selective deposition of metallicmaterials and metal oxides, relative to organic materials such as thepassivation layers disclosed herein, can be facilitated by employinghydrophobic reactants. After selectively forming a passivation layer onthe first surface, in some embodiments a metal oxide is selectivelydeposited on the second surface by contacting the substrate alternatelyand sequentially with a first hydrophobic reactant comprising a metal ofthe metal oxide and a second reactant comprising oxygen. In someembodiments, the second reactant is water or H₂O₂. In some embodimentsthe substrate is contacted sequentially with the first and secondreactants, similar to the sequence of FIG. 4A, except that a non-organiclayer is selectively deposited on or over the second surface (see, e.g.,FIGS. 1A-3B).

The hydrophobic reactant comprises one or more hydrophobic ligands. Insome embodiments, the hydrophobic reactant comprises two to fourhydrophobic ligands. In the case of hydrophobic reactants comprising ametal with a valence/oxidation state of n, in some embodiments, thehydrophobic precursor comprises n-1 or n-2 hydrophobic ligands.

In some embodiments, at least one hydrophobic ligand comprises only Cand H. In some embodiments, at least one hydrophobic ligand comprises C,H and Si or Ge, but no additional elements.

In some embodiments, a hydrocarbon ligand comprises one or more of thefollowing:

-   -   C1-C10 hydrocarbon (single, double or triple bonded)        -   Alkyls            -   C1-C5 alkyls                -   Me, Et, Pr, ^(i)Pr, Bu, ^(t)Bu        -   Alkenyls            -   C1-C6 alkenyls        -   Cyclic hydrocarbons            -   C3-C8                -   Cyclopentadienyl                -   Cycloheptadienyl                -   Cycloheptatrienyl                -   Cyclohexyl                -   Derivatives of those        -   Aromatic            -   C6 aromatic ring and derivatives of those

In some embodiments, the hydrophobic reactant comprises no hydrophilicligands. However, in some embodiments the hydrophobic reactant maycomprise one or two hydrophilic ligands. In some embodiments, ahydrophilic ligand comprises nitrogen, oxygen and/or a halogen group.

In some embodiments, a hydrophilic ligand is an alkylamine (—NR₂, whereeach R can be alkyl, hydrogen). In some embodiments, the hydrophilicligand can be —NMe₂, —NEtMe, or —NEt₂.

In some embodiments, a hydrophilic ligand is an alkoxide, for example—OMe, —OEt, —O^(i)Pr, —O^(t)Bu.

In some embodiments, a hydrophilic ligand comprises a halide, such as achloride, fluoride or other halide.

In some embodiments, the hydrophobic precursor comprises the formula:

-   -   L_(n)MX_(y), in which        -   In some embodiments n is from 1-6;            -   In some embodiments n is from 1-4 or 3-4.        -   In some embodiments y is from 0-2;            -   In some embodiments y is from 0-1.        -   L is a hydrophobic ligand;            -   In some embodiments L is Cp or a C1-C4 alkyl ligand.        -   X is hydrophilic ligand;            -   In some embodiments X is an alkylamine, alkoxide or                halide ligand.        -   M is metal (including group 13 elements, B, Ga);            -   In some embodiments M has an oxidation state of +I up to                +VI.                -   In some embodiments M has an oxidation state of +IV                    to +V.            -   In some embodiments M can be a transition metal.                -   In some embodiments M is Ti, Ta, Nb, W, Mo, Hf, Zr,                    V, or Cr.                -    In some embodiments M is Hf, Zr, Ta or Nb.                -    In some embodiments M is Zr.                -   In some embodiments M is Co, Fe, Ni, Cu, or Zn.                -   In some embodiments the metal is not W or Mo.            -   In some embodiments M can be a rare earth metal.                -   In some embodiments M is La, Ce, or Y.            -   In some embodiments M can be a metal from groups of                2-13.                -   In some embodiments M is Ba, Sr, Mg, Ca, or Sc.            -   In some embodiments M is not a noble metal.

More generally, in some embodiments, the selective ALD process employs ametal precursor. In some embodiments, the metal of the metal precursormay be selected from the group comprising Al, Ti, Ta, Nb, W, Mo, Hf, Zr,V, Cr, Co, Fe, Ni, Cu, Zn, La, Ce, Y, Ba, Sr, Mg, Ca, or Sc, or mixturesthereof. In some embodiments, the metal may be Al.

In some embodiments, the hydrophobic reactant isBis(methylcyclopentadienyl) methoxymethyl Zirconium(IV)((CpMe)₂-Zr—(OMe)Me).

In some embodiments, the hydrophobic reactant isbis(methylcyclopentadienyl) methoxymethyl Hafnium(IV)((CpMe)₂-Hf—(OMe)Me).

In other embodiments, the selective ALD process employs an Al precursor.Examples of Al precursors include trimethyl aluminum (TMA), aluminumtrichloride (AlCl₃), dimethylaluminum isopropoxide (DMAI) and triethylaluminum (TEA). In some embodiments the aluminum precursor is aheteroleptic aluminum compound. In some embodiments the heterolepticaluminum compound comprises an alkyl group and another ligand, such as ahalide, for example Cl. In some embodiments the aluminum compound isdimethylaluminumchloride. In some embodiments the aluminum precursor isan alkyl precursor comprising two different alkyl groups as ligands. Insome embodiments the aluminum precursor is a metalorganic compound. Insome embodiments the aluminum precursor is an organometallic compound.

In some embodiments, the second reactant contributes one or moreelements to the material that is selectively deposited. For example, thesecond reactant can be an oxygen precursor used to deposit a metal oxideor a nitrogen precursor used to deposit a metal nitride.

In some embodiments, the second reactant comprises an oxygen precursor.

In some embodiments, the second reactant comprises H₂O.

In some embodiments, the second reactant comprises O₃.

In some embodiments, the second reactant comprises H₂O₂.

In some embodiments, the second reactant comprises oxygen plasma, ions,radicals, atomic O or excited species of oxygen.

In some embodiments, the second reactant comprises a nitrogen precursor.

In some embodiments, the second reactant comprises NH₃.

In some embodiments, the second reactant comprises N₂H₄.

In some embodiments, the second reactant comprises nitrogen containingplasma, ions, radicals, atomic N or excited species comprising N. Insome embodiments, the nitrogen reactant can comprise a mixture withcorresponding hydrogen species.

In some embodiments, other reactants can be utilize that contributeelements other than N or O to the deposited material. These reactantsmay be used in addition to a N or O second reactant, or may themselvesserve as a second reactant. For example, in some embodiments a sulfurreactant may be used to deposit a sulphide, a carbon reactant may beused to deposit carbon or a silicon reactant may be used to deposit asilicide.

In some embodiments, a second (or additional) reactant may be used thataid in depositing a metal or metallic film, such as an elemental metalfilm. For example, in some embodiments a hydrogen reactant may be used.

Alternatively, as described with respect to FIG. 2D, a metallicconductive film of interest can be selectively deposited on the secondsurface, a metallic surface, relative to the organic passivation layer.For example, U.S. Pat. No. 8,956,971, issued Feb. 17, 2015 and U.S. Pat.No. 9,112,003, issued Aug. 18, 2015, the entire disclosures of which areincorporated herein by reference for all purposes, teach processes forselective deposition of metallic materials on metallic surfaces relativeto non-metallic surfaces, including organic materials. As also notedabove with respect to FIG. 3A, a further dielectric layer, a metal oxidematerial, can be selectively formed over the selectively formed metallicmaterial layer prior to removal of the organic passivation layer.

In some embodiments a thin film comprising a material of interest, suchas aluminum oxide (e.g., Al₂O₃) or titanium nitride (e.g., TiN) isselectively deposited on one or more first dielectric or low-k surfacesrelative to one or more second metal surfaces, such as a copper, cobalt,titanium nitride or tungsten surfaces. An exemplary process isillustrated in FIG. 13 .

In Step 1A of FIG. 13 a substrate comprising low k surface and metalsurfaces is pretreated. As discussed above, in some embodimentspretreatment may comprise exposing the substrate to a plasma, such ashydrogen plasma. In some embodiments a non-plasma pretreatment processis conducted. For example, in some embodiments the substrate surface maybe exposed to a silicon reactant, such asN-(trimethylsilyl)dimethylamine (TMSDMA) or trimethylchlorosilane. Thereactant may be provided in a single long pulse, or in a sequence ofmultiple shorter pulses. In some embodiments the reactant is provided in1 to 25 pulses of from about 1 to about 60 seconds. In between pulses,the reaction chamber may be purged with an inert gas. The purge may be,for example for about 1 to 30 seconds.

In some embodiments the surface is contacted with an alkylaminosilanehaving the formula (R^(I))₃Si(NR^(II)R^(III)), wherein R^(I) is a linearor branched C1-C10 hydrocarbon group or a linear or branched C1-C5 alkylgroup or a linear or branched C1-C4 alkyl group, R^(II) is a linear orbranched C1-C10 hydrocarbon group or a linear or branched C1-C5 alkylgroup, a linear or branched C1-C4 alkyl group, or hydrogen, and R^(III)is a linear or branched C1-C10 hydrocarbon group or a linear or branchedC1-C5 alkyl group or a linear or branched C1-C4 alkyl group.

In some embodiments the surface is contacted with a silane having thegeneral formula (R^(I))₃SiA, wherein R^(I) is a linear or branchedC1-C10 hydrocarbon group or a linear or branched C1-C5 alkyl group or alinear or branched C1-C4 alkyl group, and A is any ligand which isreactive with the silicon containing surface. That is, the silane bondsto the surface through ligand A, or ligand A forms an bond to thesurface but then ligand A may migrate away from the surface and/orsilane.

The temperature of the pretreatment process may be, for example, fromabout 100 to about 300° C. The pressure during the pretreatment processmay be, for example, from about 10⁻⁵ to about 760 Torr, or in someembodiments from about 1 to 10 Torr or about 0.1 to about 10 Torr. Insome embodiments, a pretreatment or cleaning process may be carried outin situ, that is in the same reaction chamber as a selective depositionprocess.

In Step 1B, an inhibitor, such as an organic material like a polyimide,is selectively deposited on the metal surfaces. The inhibitor may bedeposited as described herein. In some embodiments the depositiontemperature is about 160 to about 220° C. The reaction chamber pressuremay be, for example, from about 10⁻⁵ to about 760 Torr, or in someembodiments from about 1 to 10 Torr or about 1 to 25 Torr. In someembodiments a vapor deposition cycle for depositing a polyimideinhibitor is carried out from about 1 to 1000 times.

In some embodiments a polyimide inhibitor is deposited by alternatelyand sequentially contacting the substrate with DAH and PDMA. The DAH andPDMA may be alternately and sequentially provided to the reaction spaceby pulses with a pulse length of about 0.1 to 10 s, followed by a purgeof about 0.1 to 10 s between pulses.

In Step 1C, a cleanup process is carried out to remove any inhibitorthat is present on the low-k surfaces. The cleanup process may compriseH₂ plasma treatment. The cleanup process may be carried out as describedherein. In some embodiments the cleanup process is carried out at atemperature of about room temperature to about 400° C. Plasma power ofabout 10 to 1000 W or about 25 to 250 W may be used to generate a plasmain flowing H₂, for example at a flow rate of about 10 to 500 sccm. Theclean time after inhibitor deposition may be, for example, from about 1to 600 seconds.

In Step 1D a bake is carried out. The bake may, for example, densify theinhibition layer and make it more robust, for example against highertemperature processes that follow. In some embodiments the bake iscarried out at a temperature of about 100 to about 800° C., for exampleabout 300 to about 600° C. In some embodiments the bake step is carriedout at a temperature greater than 300° C. In some embodiments the bakestep is carried out at a temperature of about 400° C. In someembodiments the bake time is about 1 to about 15 minutes. The bake maycomprise two steps—a first step at a lower temperature and a second stepat a higher temperature. For example, the bake may comprise a first stepat a temperature of about 250° C. and a second step at a temperature ofabout 400° C. In some embodiments the first and second steps are carriedout for the same amount of time. In other embodiments they are carriedout for different amounts of time.

In some embodiments the bake is carried out in the same reactor as thesubsequent selective deposition of the material of interest. In someembodiments the bake is carried out in the same reactor as thedeposition of the inhibitor. In some embodiments the bake is carried outin a separate reaction chamber.

In Step 1E a material is selectively deposited on the dielectric surfacerelative to the metal surfaces comprising the inhibitor by a vapordeposition process. Selective deposition may be as described herein.

In some embodiments aluminum oxide is deposited in Step 1E byalternately contacting the substrate with an aluminum reactant and anoxygen reactant. The aluminum reactant may comprise, trimethyl aluminum(TMA), aluminum trichloride (AlCl₃), dimethylaluminum isopropoxide(DMAI) and triethyl aluminum (TEA). In some embodiments the aluminumprecursor is a heteroleptic aluminum compound. In some embodiments theheteroleptic aluminum compound comprises an alkyl group and anotherligand, such as a halide, for example Cl. In some embodiments thealuminum compound is dimethylaluminumchloride. In some embodiments, thealuminum precursor is an alkyl precursor comprising two different alkylgroups as ligands. In some embodiments, the aluminum precursor is ametalorganic compound. In some embodiments, the aluminum precursor is anorganometallic compound. The oxygen reactant may comprise, for example,water or H₂O₂. In some embodiments, aluminum oxide may be deposited byan atomic layer deposition process in which the substrate is alternatelyand sequential contacted with dimethylaluminum isopropoxide (DMAI) andwater or H₂O₂. In some embodiments, the temperature in the reactionchamber during aluminum oxide deposition is from about 150 to about 350°C. The pulse time for the reactants may be from about 0.1 to about 10seconds, and the purge time between reactant pulses may also be fromabout 0.1 to about 10 seconds. The reaction chamber pressure may be, forexample, from about 10- to about 760 Torr, or in some embodiments fromabout 1 to 10 Torr.

In some embodiments titanium nitride is deposited in Step 1E byalternately contacting the substrate with a titanium reactant and anitrogen reactant. The titanium reactant may comprise, for example,TiCl₄. The nitrogen reactant may comprise, for example, NH₃. In someembodiments TiN may be deposited by an atomic layer deposition processin which the substrate is alternately and sequential contacted withTiCl₄ and NH₃. In some embodiments the temperature in the reactionchamber during titanium nitride deposition is from about 250 to about500° C. The pulse time for the titanium reactant may be from about 0.2to about 10 seconds, and the pulse time for the nitrogen reactant may befrom about 0.1 to about 10 seconds. The purge time between reactantpulses may also be from about 0.1 to about 10 seconds. The reactionchamber pressure may be, for example, from about 10⁻⁵ to about 760 Torr,or in some embodiments from about 1 to 10 Torr. The titanium nitridelayer was deposited using the process flow illustrated in FIG. 13 .

In Step 1F the substrate is subjected to a post-deposition cleaning stepto remove the inhibitor from the metal surfaces, such as treatment withH₂ plasma. The cleaning step may comprise H₂ plasma treatment. Thecleaning process may be carried out as described herein. In someembodiments the cleaning step is carried out at a temperature of aboutroom temperature to about 400° C. Plasma power of about 10 to 2000 W, 25to 1000 W or 25 to 250 W may be used to generate a plasma in flowing H₂,for example at a flow rate of about 10 to 500 sccm. The clean time afterdeposition of the layer of interest may be, for example, from about 1 to600 seconds.

In some embodiments a thin film comprising a material of interest, suchas aluminum oxide (e.g., Al₂O₃) or titanium nitride (e.g., TiN) isselectively deposited on a first surface of a three-dimensionalstructure relative to one or more second surfaces. The three-dimensionalstructure may comprise, for example, a via or a trench. In someembodiments an inhibitor, such as a polyimide layer, is non-selectivelydeposited on the three-dimensional structure. The inhibitor is thenpatterned to expose the region on which selective deposition is desired.For example, anisotropic etching can be used to remove the layer fromsurfaces on which deposition is desired. Vapor deposition is thencarried out to deposit the layer of interest on the areas that are notcovered with inhibitor.

An exemplary process for selective deposition on a three-dimensionalstructure is illustrated in FIG. 14 . A structure comprising a trench orvia opening is illustrated. As shown in Step 2A, an inhibitor isconformally deposited on the feature. The inhibitor may be deposited asdescribed herein. For example, a polyimide may be vapor deposited asdescribed herein. In Step 2B, the inhibitor is removed from the bottomof the trench by anisotropic etch. As illustrated in Step 2C, followingetch the inhibitor is baked and the layer of interest is selectivelydeposited on the exposed surface at the bottom of the trench relative tothe surfaces comprising the inhibitor. Finally, as illustrated in Step2D, the inhibitor material is removed from the remaining surfaces.Although not illustrated, additional pretreatment steps may be carriedout as described herein.

Passivation Blocking Layer

As noted above, a self-assembled monolayer (SAM) can serve to inhibitdeposition of an organic passivation layer, thus facilitating selectivedeposition of the organic passivation layer on other surfaces. The term“blocking” is thus merely a label and need not imply 100% deactivationof the organic passivation layer deposition. As noted elsewhere herein,even imperfect selectivity can suffice to obtain a fully selectivestructure after an etch back process.

In one embodiment, a passivation blocking layer is formed on the secondsurface to inhibit deposition of for comprises an SAM containing sulfur.In one embodiment, the second surface is a metallic surface. In oneembodiment, the metallic surface is pretreated with acid treatmentsprior to SAM formation.

Deposition Equipment

Examples of suitable reactors that may be used in the selectivedeposition processes described herein include commercially available ALDequipment. In addition to ALD reactors, many other kinds of reactorscapable of growth of organic passivation layers, including CVD reactors,VDP reactors, and MLD reactors, can be employed.

The selective dielectric on dielectric deposition described herein withrespect to FIGS. 1A-1D could be performed in up to five processes. (1)pretreatment, (2) selective organic passivation layer deposition on thefirst surface; (3) partial etch back, also referred to as a “clean-up”etch, of any organic material from over the second surface, (4)selective dielectric deposition on the second surface; and (5) removalof the organic passivation layer from over the first surface.

In one embodiment, tools for the sequence can be minimized by combiningthe (2) selective organic passivation layer deposition and the (3)partial etch-back in one chamber, and using a clustered chamber toconduct the (4) selective dielectric deposition on the second surface.The pretreatment can either be performed on another platform (e.g., wetbench) or omitted through tuning of certain recipes. The organicpassivation layer removal may be performed in a separate ashing tool,such as those often used for removal of photoresist and other organicmaterials, or in the deposition chamber using the same or a similarchemistry used for the partial etch back of organic material. Thus, thedeposition stages and intervening etch back can be performed in platformthat comprises 2 reactors, including either 4 or 8 processing stations,for the polyimide deposition and etch back; and 2 reactors, includingeither 4 or 8 processing stations, for the selective dielectricdeposition.

In some embodiments a cluster tool comprising three or more reactionchambers. For example, a first chamber may be used for one or both ofpretreatment and etch processing. A second chamber may be used fordeposition of the organic layer, and a third chamber may be used forselective deposition of the film of interest. A bake process may becarried out in situ in the same chamber as the selective deposition ofthe film of interest, or may be carried out in a different chamber.

In some embodiments, selective deposition processes as described hereincan be performed in at least six processes, as illustrated in FIG. 13 .(Step 1A) pretreatment, (Step 1B) selective inhibitor deposition, suchas deposition of an organic layer deposition on a first surface; (Step1C) partial etch back, also referred to as a “clean-up” etch, of anyorganic material from over the second surface, (Step 1D) bake of theorganic layer; (Step 1E) selective deposition on the second surface; and(Step 1F) removal of the organic layer from over the first surface.

Referring to FIG. 5 , an apparatus 100 is provided for conductingpolymer deposition and organic material etch back in situ. The apparatus100 includes a reaction chamber defines a reaction space 115 configuredto accommodate at least one substrate 120. The apparatus 100 alsoincludes a first reactant vessel 105 configured for vaporizing a firstorganic reactant 110 to form a first reactant vapor. A gas line 130fluidly connects the first reactant vessel 105 to a reaction space 115within which a substrate 120 can be accommodated. The gas line 130 isconfigured to selectively transport the first reactant vapor from thefirst reactant vessel 105 to an inlet manifold 135 to the reaction space115. The apparatus 100 also includes a second reactant vessel 140holding a second reactant 145. In some embodiments, the second reactant145 is naturally in a gaseous state; in other embodiments, the secondreactant vessel 140 is also configured to vaporize the second reactant145 from a natural liquid or solid state. The second reactant vessel 140is in selective fluid communication with the inlet manifold 135. Theinlet manifold 135 can include a shared distribution plenum across thechamber width, in a showerhead or cross-flow configuration, or canmaintain separate paths to the reaction space 120 for separatereactants. For sequential deposition embodiments, it can be desirable tokeep the reactant inlet paths separate until introduction to thereaction space 115 in order to avoid reactions along the surface ofcommon flow paths for multiple reactants, which can lead to particlegeneration. The apparatus can in some embodiments include additionalvessels for supply of additional reactants.

The illustrated apparatus 100 also includes a plasma source 147.Although illustrated schematically as if attached to the reaction space115, the skilled artisan will appreciate that the plasma source maybe bea remote plasma source external to the reaction space 115, or may be anin situ plasma generator for direct plasma generation (e.g.,capacitively coupled) within the reaction space 115. Alternatively oradditionally, an ozone generator may be employed for removal of organicmaterial.

One or more additional gas source(s) 150 is (are) in selective fluidcommunication with the first reactant vessel 105, the reaction space 115and the plasma source 147 (to the extent separate from the reactionspace 115). The gas source(s) 150 can include inert gases that can serveas purge and carrier gases, and other gases (e.g., Ar/H₂) for plasmaetch back. Inert gas supply from the gas source(s) can also be inselective fluid communication with the second reactant vessel 140, asshown, and any other desired reactant vessels to serve as a carrier gas.

A control system 125 communicates with valves of the gas distributionsystem in accordance with organic passivation layer deposition and etchback methods and described herein. The control system 125 typicallyincludes at least one processor and a memory programmed for desiredprocessing. For sequential deposition processing, the valves areoperated in a manner that alternately and repeatedly exposes thesubstrate to the reactants, whereas for simultaneous supply of thereactants in a conventional CVD process, the valves can be operated tosimultaneously expose the substrate to mutually reactive reactants.

An exhaust outlet 155 from the reaction space 115 communicates throughan exhaust line 160 with a vacuum pump 165. The control system 125 isconfigured to operate the vacuum pump 165 to maintain a desiredoperational pressure and exhaust excess reactant vapor and byproductthrough the exhaust outlet 155.

The control system 125 can also control pressure and temperature invarious components of the apparatus 100. For example, the control systemcan be programmed to keep the substrate 120 at a suitable temperaturefor the processes being performed. In one embodiment, control system 125is also configured to maintain the first reactant 110 in the firstreactant vessel 105 at a temperature A, and is configured to maintainthe substrate 120 in the reaction space 115 at a temperature B, wherethe temperature B is lower than the temperature A. In an embodiment, thecontrol system 125 or a separate temperature control is also configuredto maintain the gas line 130 at a temperature C, where the temperature Cis higher than the temperature A.

Accordingly, the apparatus 100 includes source vessels 105, 140 forvaporizing and supplying the reactants described above for polymerdeposition (e.g., one vessel for a diamine and one vessel for adianhydride precursor). The plasma source 147 communicates with gassource(s) 150 that include a source of H₂ and inert gas (e.g., noblegas, such as argon or helium). Additionally, the apparatus 100 includesa control system 125 programmed to supply gases and operate the plasmasource in a manner to perform the polymer deposition described herein,as well as a hydrogen plasma etch back. The control system 125 maintainsthe substrate 120 in a range of 180° C. to 220° C., or about 190° C. to210° C., such that the polymer deposition and etch back can be conductedat the same temperature sequentially, without removing the substrate 120from the reaction space 115. The etch back may be from 0.5-600 seconds,1-120 seconds, 1-60 seconds, 1-20 seconds, 2-15 seconds, and 5-15seconds. As another example, a pulsed ozone (O₃) etch process may beused for the etch back process. As the skilled artisan will appreciate,process conditions may be modified for slower and more controlledetching for the purpose of partial etch back to minimize overetching ofthe desired passivation layer on the first surface. Indeed, etch ratedepends strongly upon etch temperature for O₃ etching of polymer.Combining the selective deposition of the passivation layer with thepartial etch back would not increase process time of the single chambermuch, as the etch process is typically very short. The same equipmentand etchants can also be used for removal of the passivation layer.

The apparatus 100 configured for polymer deposition and etch back, couldbe a showerhead reactor with solid source vessels for DAH (with avaporization temperature of about 40° C.) and PMDA (with vaporizationtemperature of about 170° C.). In one embodiment, the plasma source 147comprises an in situ direct plasma (e.g., capacitively coupled)apparatus with argon and H₂ supply for the in situ etch back. In anotherembodiment, the apparatus 100 may be a cross-flow reactor rather than ashowerhead reactor, but still having the above-noted with solid sourcevessels 105, 140 and direct plasma capability. In another embodiment,the plasma source 147 comprises a remote plasma is coupled to thereaction space 115 to supply plasma produces from an Ar/H₂ plasma. Inanother embodiment, the plasma source 147 could be replaced with anozone generator coupled to the reaction space 115. The remote plasma orozone generator could, for example, be connected to a showerheadreactor.

The polymer deposition apparatus 100 desirably includes self-cleaningcapability to keep the reaction space 115 and exhaust lines 160 cleanafter multiple depositions. In some embodiments, the in situ or remoteAr/H₂ plasma source 147 noted above for etch back can be adapted forperiodic chamber cleaning, possibly under higher power or temperatures,as it can operate in the absence of production substrates and onlyperiodically (rather than every wafer). Alternatively, the polymerdeposition chamber can be provided with a remote plasma supplied withNF₃ etch, or an ozone supply to conduct periodic chamber cleans. In someembodiments, an O₃/N₂ supply can be adapted for periodic chambercleaning, possibly under higher power or temperatures compared to thepolymer partial etch back or removal processes, as the chamber cleanprocess operates in the absence of production substrates and onlyperiodically (rather than every wafer).

Line Edge Position

Referring to FIG. 6 and in some embodiments, as described above,selective deposition on a second surface can be accomplished byselective passivation of a first surface following selective depositionof a dielectric, such as ZrO₂, on the second surface. In the illustratedflow chart, the first surface can be metallic (e.g, an embedded metalfeature in an integrated circuit interlevel dielectric, or ILD), and thesecond surface can be dielectric (e.g., the ILD). The passivation cancomprise a polymer or other organic material selectively deposited onthe first surface relative to the second surface of a part in Step 1.Subsequently, a polymer etch back, sometimes referred to as a “clean-up”etch to perfect the selectivity, is performed to remove polymer that mayhave deposited on the second surface in Step 2, without removing all ofthe polymer from the first surface. As the polymer acts as a passivationlayer, a dielectric material is selectively deposited on the secondsurface in Step 3. Any number of suitable dielectric materials may beused in Step 3. In some embodiments, the dielectric material may beselected from ZrO₂ and other metal oxides, such as transition metaloxides or aluminum oxide, or other dielectric oxides including mixtureshaving etch selectivity over SiO₂-based materials or slow etch rate inconditions in which SiO₂-based materials are etched. Even though somesuch metal oxides may have high k values, higher than 5 or even higherthan 10, they are thin, are located in positions that avoid significantparasitic capacitance in metallization structures, and advantageouslyallow for masking surfaces against selective etching of silicon oxidematerials. In other embodiments, the dielectric can be a silicon oxidebased material, but may be thicker to serve as an etch mask as describedherein. In Step 4 of FIG. 6 , the polymer passivation is removed fromthe first surface.

FIG. 7 illustrates the effect that etch back time for removal of thepassivation (e.g., polymer or other organic layer) from the secondsurface has on the dielectric layer formed. More specifically, theposition of the edge of the selectively formed dielectric layer can becontrolled relative to the boundary between the underlying metallic anddielectric surfaces by selecting the extent of the intermediate polymeretch back process. In an embodiment, polymer is deposited on the firstsurface relative to the second surface of a part, as describedpreviously in Step 1 of FIG. 6 , as seen in the 1^(st) row ofillustrations in FIG. 7 . As seen in the polymer as depositedillustration, the deposition of the polymer on the first surface createsa thicker polymer layer surface over the first surface, with arelatively thin polymer layer over the second surface, consequentlyhaving a downwardly sloped polymer thickness from the first surface tothe second surface at the first-second surface boundary. Subsequently, apolymer etch back, as described previously in Step 2 of FIG. 6 , may beperformed for varying durations (or for the same durations withdifferent etch rates, such as by different temperatures or etchantconcentrations, or for different durations and different etch rates) tocontrol the thickness and shape of the polymer layer, as seen in the2^(nd) through 6^(th) rows of the first column of illustrations in FIG.7 . The etch back may be isotropic or anisotropic. In some embodiments,a polymer etch time is minimal and the polymer etch does not removesufficient polymer to expose the second surface, as seen in the 2^(nd)row of illustrations in FIG. 7 . In this case, the subsequent selectivedielectric deposition does not work because both the first and secondsurfaces are covered with the passivation layer, and even if a smallamount of dielectric deposits it will be removed by a lift-off processwith removal of the passivation layer. In some embodiments, a polymeretch time is selected to remove the majority of the polymer formed fromthe second surface, but leave a polymer layer leading edge that extendsover the first-second surface boundary onto the second surface, as seenin the 3^(rd) row of illustrations in FIG. 7 . In this case, subsequentselective deposition of the dielectric and removal of the polymer leavesa gap between the deposited dielectric edge and the first-second surfaceboundary. In some embodiments, a polymer etch time is selected to removethe polymer from the second surface, and a polymer layer edge is leftaligned with the first-second surface boundary. In this case, subsequentselective deposition of the dielectric and removal of the polymer leavesthe bottom surface edge of deposited dielectric aligned with thefirst-second surface boundary. In some embodiments, a polymer etch timeis selected to remove the polymer from the second surface and a portionof the polymer from the first surface, and a first gap exists between apolymer layer leading edge and first-second surface boundary, as seen inthe 5′ row of illustrations in FIG. 7 . In this case, subsequentselective deposition of the dielectric and removal of the polymer leavesthe deposited dielectric extending over the first-second surfaceboundary and overlapping with the first surface. If the polymer etchtime is performed for an extended period of time and the polymer etchcompletely removes the polymer from both the first surface and thesecond surface, as seen in the 6^(th) row of illustrations in FIG. 7 ,then subsequent dielectric deposition is not selective.

Thus, selective dielectric selective deposition and partial polymer etchback, as described previously in Steps 3 and 4 of FIG. 6 , may beperformed to create various relationships between the edge of theselectively deposited dielectric layer on the second surface and theinterface between the first and second surfaces, depending on the extentof the passivation etch back following its selective deposition, as seenin the right-most images of the 2^(nd) through 6^(th) rows of the thirdcolumn of illustrations in FIG. 6 . In some embodiments, no dielectriclayer is formed because the polymer layer passivated the second surface,as seen in the 2^(nd) row of illustrations in FIG. 7 . In someembodiments, a gap exists between a dielectric on the second surfacefirst surface, as seen in the 3^(nd) row of illustrations in FIG. 7 . Insome embodiments, the dielectric layer edge is aligned with thefirst-second surface boundary, as seen in the 4^(th) row ofillustrations in FIG. 7 . In some embodiments, the dielectric layeroverlaps the first surface, as seen in the 5^(th) row of illustrationsin FIG. 7 . In some arrangements, the dielectric layer forms on both thefirst surface and the second surface because no polymer layer passivatedthe first surface.

FIG. 8 illustrates the effect that passivation layer depositionthickness has on the dielectric layer formed. More specifically, theposition of the edge of the selectively formed dielectric layer can becontrolled relative to the boundary between the underlying metallic anddielectric surfaces by selecting the thickness of the intermediatepolymer passivation layer. As passivation layer deposition thicknessincreases, the passivation layer thicknesses on both the first surfaceand second surface are increased. However, because the passivation layeris selectively deposited on the first surface, the passivation thicknessover the second surface increases less than the passivation layerthickness over the first surface. Therefore, a passivation etch back,dielectric deposition and passivation removal will create selectivedielectric layers with varying positions relative to the first-secondsurface boundary. In some embodiments, a passivation layer is depositedwhich produces a gap between a selectively deposited dielectric layeredge and the first-second surface boundary, as seen in as seen in the1^(st) column of illustrations in FIG. 8 . In some embodiments, athicker polymer layer is deposited which produces a larger gap between aselectively deposited dielectric layer edge and the first surface, asseen in as seen in the 2^(nd) column of illustrations in FIG. 8 .

FIG. 9 illustrates the effect selectively deposited dielectric thicknesshas on the relative positions of the dielectric layer formed and thefirst-second surface boundary. More specifically, the position of theedge of the selectively formed dielectric layer can be controlledrelative to the boundary between the underlying metallic and dielectricsurfaces by selecting the thickness of the selective dielectric layer.As dielectric deposition thickness selectively deposited on the secondsurface increases, the dielectric overhang edge increasingly extendsfurther past the first-second surface boundary. In some embodiments, adielectric layer is deposited which produces a certain overhangstructure, as seen in as seen in the 1^(st) column of illustrations inFIG. 9 . In some embodiments, a thicker dielectric layer is depositedwhich produces a greater overhang, as seen in as seen in the 2^(nd)column of illustrations in FIG. 9 . In some embodiments, an even thickerdielectric layer is deposited which produces an even greater dielectricoverhang over the first surface, as seen in as seen in the 3^(rd) columnof illustrations in FIG. 9 . For certain subsequent processes, such asanisotropic processing (e.g., anisotropic reactive ion etching), theextent of the overhang can shadow portions of the first surface andprotect against the subsequent processing.

Thus, in some embodiments, though largely selectively formed over thedielectric surface similar to FIG. 1D, the dielectric layer isselectively deposited to produce an overhang and/or overlap with themetallic feature. In some embodiments, the dielectric layer does notcomprise an overhang or overlap, and the edge of the selectivelydeposited dielectric on dielectric can be aligned with the edge of themetallic feature or there can be a gap between the edge of theselectively deposited dielectric layer and the metallic feature. Becauseof the selective deposition techniques taught herein, the selectivelydeposited dielectric layer may have features characteristic of selectivedeposition, without the use of traditional masking and etching topattern the dielectric layer. For example, the edge of the dielectriclayer may be tapered with a slope of less than 45 degrees, rather thanhaving a vertical or steeply sloped sidewall, as is typical ofphotolithographically patterned layers. This characteristic etch profilemay remain whether or not the selectively deposited layer was subjectedto a clean-up etch, or partial etch back.

FIGS. 10A-10D illustrate how topography can affect the relationshipbetween a selectively deposited dielectric and the boundary betweenfirst and second surfaces

FIG. 10A illustrates a planar structure that results in an edge of aselectively deposited dielectric 2502 being aligned with thefirst-second surface boundary. The first surface that is passivated by apassivation layer 2504, for example a polymer material, can be definedby a metallic material, such as embedded metal 2506, and the secondsurface can be defined by a low k dielectric, such as an interleveldielectric (ILD) 2508. The passivation layer 2504 is selectivelydeposited over the first surface and the dielectric layer 2502 isselectively deposited over the second surface, wherein the edge of thedielectric layer 2502 is aligned with the first-second surface boundary.

FIG. 10B illustrates a recessed first surface relative to the secondsurface. As above, the first surface can comprise a metallic material2506 embedded and recessed with in a low k dielectric material 2508 thatdefines the second surface. The passivation layer 2504 is selectivelyformed over the first surface within the recess. The dielectric layer2502 is disposed over the second surface and over the recess walls,wherein the edge of the dielectric layer 2502 meets the surface of thepassivation layer 2504. Removal of the passivation layer 2504 willresult in the dielectric layer 2502 selectively formed on the secondsurface but overlapping with the first surface (e.g., metallic feature2506).

FIG. 10C illustrates an elevated first surface with respect to thesecond surface. The first surface can be defined by a metallic material2506 embedded in and protruding above the second surface, which can be alow k dielectric material 2508. The passivation layer 2504 is disposedover the first surface, including protruding side walls, and thus atleast partially disposed over the second surface. The dielectric layer2502 is disposed over the second surface but is spaced from the firstsurface by the thickness of the passivation material 2504 on the sidewalls. Thus, after removal of the passivation layer 2504, there is a gapbetween the dielectric layer 2502 and the first surface (e.g.,protruding metallic feature 2606)

FIG. 10D illustrates a recessed first surface of some embodiments. Inthis case, after removal of the passivation layer 2504, a gap is leftbetween the selectively deposited dielectric layer 2502 on the secondsurface and the first surface. In this case, the gap takes the form of avertical sidewall of the second surface, which is then exposed tosubsequent processing.

Thus, FIGS. 7-10D illustrate variables that can be adjusted to tune theposition of a selectively deposited dielectric 2502 (e.g., on dielectricsecond surface) relative to an interface between the first and secondsurfaces (e.g., between a metallic feature 2506 and low k dielectric2508). In particular, FIG. 7 shows how extent or time for passivationlayer etch back can affect the relative positions; FIG. 8 shows howthickness of the selectively deposited passivation layer can affect therelative positions; FIG. 9 shows how thickness of the selectivelydeposited dielectric layer can affect the relative positions; and FIGS.10A-10D show how topography of the first and second surfaces can affectthe relative positions. These variables can thus be adjusted to affectwhether the selectively deposited dielectric on the second surface isaligned with, has a gap relative to, or overlaps the first surface.

Example Applications

FIGS. 11A-11E illustrate a device and process of creating a device, insome embodiments, with improved electrical isolation. FIG. 11Aillustrates a partially fabricated integrated circuit with an embeddedmetallic feature 2606 that defines a first surface which is flush with asecond surface, defined by the surrounding low k material 2608, similarto the planar structure shown in FIG. 10A. The metallic featurecomprises a first material further comprising Cu 2610 and TaN barriermaterial 2612 positioned within a first low-k dielectric material 2608.

FIG. 11B illustrates the device of FIG. 11A subsequent to a conductivebarrier layer 2614 over the first material. In some embodiments, thebarrier layer 2614 may be W. While illustrated as protruding, in someembodiments the barrier material 2614 over the Cu 2610 line or via maybe embedded in and flush with the surrounding low k material 2608.

FIG. 11C illustrates the device of FIG. 11B subsequent to the selectivedeposition of a passivation layer 2604 over the first surface nowdefined by the metallic barrier layer 2614 (W), wherein edges of thefirst surface are exposed. In some embodiments, the passivation layer2604 may be an organic material, such as a polymer. In some embodiments,the selective deposition of the passivation layer 2604 is followed by anetch back of the passivation layer material sufficient to expose some ofthe metallic first surface.

FIG. 11D illustrates the device of FIG. 11C subsequent to the selectivedeposition of a dielectric layer 2602 over the second surface,overlapping with the metallic first surface. In some embodiments, thedielectric layer 2602 may be a high-k material. In some embodiments, thehigh-k material may be ZrO₂. In some embodiments, the selectivedielectric layer 2602 may be a low-k material, such as SiOC, Al₂O₃, andSiN. In some embodiments, the selectively deposited dielectric material2602 may serve as an etch stop with respect to subsequent etches throughlow k material 2608 to open trenches or vias that expose the metallicbarrier material 2614.

FIG. 11E illustrates the device of FIG. 11D subsequent to removal of thepolymer passivation layer 2604, thereby exposing the underlying metallayer surface (of barrier material 2614 in this case). The selectivedielectric 2602 overlaps the metallic first surface defined by barrierlayer 2614 and reduces the risk of shorting when a subsequent metallicfeature (e.g., overlying metal line or via) is formed thereover. Inparticular, a low k material is deposited over the structure of FIG.11E, and openings are created and filled with metal. The openings arecreated by masking and selective low k etching, and the etch stops onthe selectively deposited dielectric (e.g., ZrO₂). The overlap of theselectively deposited dielectric 2602 with the metallic feature definedby the barrier layer 2614, resulting from the selection of conditionsduring the passivation, etch-back, dielectric deposition and/ortopography, protects against misalignment. Thus the overlap preventscontact with adjacent metallic features or undesired etching of thelower low k material 2608. Note that the selectively depositeddielectric material 2602 can stay in the final integrated circuitdevice, having served as an etch stop between ILD layers. Althoughordinarily high k materials are avoided in metallization processes,parasitic capacitance is minimal. Minimal parasitic capacitance is dueto the predominant position of the high k material over the low kmaterial, the thinness of the high k material due to its functions, andthe advantage of high selectivity for this dielectric capping layer overhigh k material outweighs slight parasitic capacitance introduced by thematerial selection. Of course, high etch selectivity may also beachieved with lower k materials to be selectively deposited on the ILD.

FIGS. 12A-12B illustrate a device and process of creating a device, insome embodiments, with air-gaps, which may be desirable for a variety ofreasons, such as reduction of parasitic capacitance between closelyspaced metallic features (e.g., metal lines) in an integrated circuit.FIG. 12A illustrates planar surface of a partially fabricated integratedcircuit of some embodiments, similar to the device previously shown inFIG. 10A. The initial structure may be a first surface defined by ametallic feature 2706 (e.g., Cu line with dielectric and barrier liners)surrounded by a second surface defined by dielectric material 2608(e.g., low k ILD). A passivation layer 2704 is selectively depositedover the first surface, and an etch back performed to expose the secondsurface in a manner that leaves the passivation layer 2704 over thefirst surface and partially over the second surface. A dielectric 2702is selectively deposited over the second surface, wherein the dielectriclayer edge is spaced away from the first-second surface boundary ontothe second surface. FIG. 12B illustrates the device of FIG. 12Asubsequent to the removal of the passivation layer 2704 to expose thefirst surface and partially expose the second surface previously coveredby the first material, leaving a gap 2710 between the selectivelydeposited dielectric material and the first surface (metallic feature2706). Subsequently selectively etching the exposed second materialforms cavities 2712 in those gaps 2710 next to the metallic features. Insome embodiments, the second material that is selectively etched is SiO.In some embodiments, selective etching is an HBr dry etch. An HBr dryetch can selectively etch silicon oxide at about 6-8 nm/min, whereascertain other materials are etched at lower rates such as siliconnitride (<0.3 nm/min) and zirconium oxide (<0.3 nm/min), and likely willnot etch tungsten without chlorine (e.g., Cl₂) or sulfur hexafluoride(e.g., SF₆). Deposition of a third material 2714, such as standard low kmaterial, with sufficiently low conformality leaves air-gaps 2716 withinthe low k material 2708 adjacent to a lateral sides of the metallicfeatures 2706. As is known in the art, the air cavities lower theoverall k value of the ILD and reduce parasitic capacitance betweenmetallic features.

Although certain embodiments and examples have been discussed, it willbe understood by those skilled in the art that the scope of the claimsextend beyond the specifically disclosed embodiments to otheralternative embodiments and/or uses and obvious modifications andequivalents thereof.

What is claimed is:
 1. A method of selective deposition on a seconddielectric surface of a substrate relative to a first metal or metallicsurface of the substrate, the method comprising, in order: treating thefirst and second surfaces by exposing the substrate to a silane;selectively forming a polymer layer from vapor phase reactants on thefirst surface relative to the second surface; baking the polymer layer;controlling a position of an edge of a dielectric layer to be depositedrelative to a boundary between the underlying first and second surfaces;and depositing the dielectric layer on the second surface of thesubstrate from vapor phase reactants.
 2. The method of claim 1, whereinthe silane comprises an alkylaminosilane.
 3. The method of claim 2,wherein treating comprises exposing the substrate toN-(trimethylsilyl)dimethylamine (TMSDMA) or trimethylchlorosilane. 4.The method of claim 1, wherein baking comprises heating the substrate toa temperature of about 200 to about 500° C.
 5. The method of claim 1,wherein selectively forming the polymer layer comprises selectivelyvapor depositing an organic polymer layer on the first surface.
 6. Themethod of claim 5, wherein the organic polymer layer is a polyimidelayer.
 7. The method of claim 1, wherein the dielectric layer isdeposited by an atomic layer deposition process.
 8. The method of claim1, wherein the dielectric layer comprises a metal oxide.
 9. The methodof claim 8, wherein the metal oxide comprises a dielectric transitionmetal oxide.
 10. The method of claim 1, wherein the dielectric layercomprises ZrO2.
 11. The method of claim 1, wherein the substratecomprises a partially fabricated integrated circuit with an embeddedfeature in which the first metal or metallic surface is flush with thesecond dielectric surface.
 12. The method claim 1, wherein controllingthe position of the edge comprises controlling the position so that theedge of the dielectric layer is aligned with the boundary between thefirst and second surfaces.
 13. The method of claim 1, wherein thecontrolling comprises etching the polymer layer for a selected polymeretch time and leaves at least some polymer layer on the first surface.14. The method of claim 13, wherein etching comprises an anisotropicetch.
 15. The method of claim 13, wherein etching comprises an isotropicetch.
 16. The method of claim 13, wherein a polymer is formed on thesecond surface, and the selected polymer etch time allows a portion ofthe polymer from the second surface to be removed during the etchingwhile leaving the edge that extending over the boundary between theunderlying first and second surfaces.
 17. The method of claim 16,further comprising, after depositing the dielectric layer, removing thepolymer layer, resulting in a gap between an edge of the depositeddielectric layer and the boundary between the underlying first andsecond surfaces.
 18. The method of claim 16, wherein the selectedpolymer etch time allows any polymer from the second surface to becompletely removed and leaves the edge aligned with the boundary betweenthe underlying first and second surfaces.
 19. The method of claim 16,wherein the selected polymer etch time allows any polymer from thesecond surface to be completely removed and allows a portion of thepolymer layer from the first surface to be removed.
 20. The method ofclaim 19, wherein the deposited dielectric layer extends over theboundary between the underlying first and second surfaces.